Novel aspects of ethylene glycol catabolism.

Ethylene glycol (EG) is an industrially important two-carbon diol used as a solvent, antifreeze agent, and building block of polymers such as poly(ethylene terephthalate) (PET). Recently, the use of EG as a starting material for the production of bio-fuels or bio-chemicals is gaining attention as a sustainable process since EG can be derived from materials not competing with human food stocks including CO2, syngas, lignocellulolytic biomass, and PET waste. In order to design and construct microbial process for the conversion of EG to value-added chemicals, microbes capable of catabolizing EG such as Escherichia coli, Pseudomonas putida, Rhodococcus jostii, Ideonella sakaiensis, Paracoccus denitrificans, and Acetobacterium woodii are candidates of chassis for the construction of synthetic pathways. In this mini-review, we describe EG catabolic pathways and catabolic enzymes in these microbes, and further review recent advances in microbial conversion of EG to value-added chemicals by means of metabolic engineering. KEY POINTS: • Ethylene glycol is a potential next-generation feedstock for sustainable industry. • Microbial conversion of ethylene glycol to value-added chemicals is gaining attention. • Ethylene glycol-utilizing microbes are useful as chassis for synthetic pathways.

Microbial xylitol production.

Xylitol is pentahydroxy sugar alcohol, existing in very trace amount in fruits and vegetables, and finds varied application in industries like food, pharmaceuticals, confectionaries, etc. and is of prime importance to health. Owing to its trace occurrence in nature and considerable increase in market demand that exceeds availability, alternate production through biotechnological and chemical approach is in process. Biochemical production involves substrates like lignocellulosic biomasses and industrial effluents and is an eco-friendly process with high dependency on physico-chemical parameters. Although the chemical processes are faster, high yielding and economical, they have a great limitation as usage of toxic chemicals and thus need to be regulated and replaced by an environment friendly approach. Microbes play a major role in xylitol production through a biotechnological process towards the development of a sustainable system. Major microbes working on assimilation of xylose for production of xylitol include Candida tropicalis, Candida maltose, Bacillus subtilis, Debaromyces hansenii, etc. The present review reports all probable microbial xylitol production biochemical pathways encompassing diverse bioprocesses involved in uptake and conversion of xylose sugars from agricultural residues and industrial effluents. A comprehensive report on xylitol occurrence and biotechnological production processes with varied substrates has been encompassed. KEY POINTS: • Xylitol from agro-industrial waste • Microbial xylose assimilation.

Screening biorefinery pathways to biodiesel, green-diesel and propylene-glycol: A hierarchical sustainability assessment of process.

Plant design implies the best choice among a set of feedstock-to-product process pathways. Multiple sustainability performance indicators can blur the decision, and existing sustainability assessment methods usually focus only on environmental life-cycle performance and corporate metrics or solely on the gate-to-gate process. It is relevant to incorporate integrated system analysis to address sustainability comprehensively. To this end, the Sustainable Process Systems Engineering (S-PSE) method was previously introduced to select the most sustainable feedstock-process-product configuration via four-dimensional indicators (environment, efficiency, health-&-safety, and economic), and then pinpoint the sustainability hotspots of the best design to unveil possible improvements. This work expands S-PSE by adding new features: (i) cradle-to-gate environmental assessment; (ii) composition of flowsheets; (iii) new indicators; (iv) statistical screening of indicators; and (v) 2030 Agenda compliance. A biorefinery case-study demonstrates S-PSE: to select the best pathway from soybean-oil, palm-oil, and microalgae-oil to biodiesel, green-diesel, and propylene-glycol. Firstly, statistical screening reduces the indicator set by 62%. Results evince all routes from microalgae-oil as economically unfeasible due to oil cost, despite superior environmental performance. S-PSE evinces palm-oil-to-biodiesel as the most sustainable due to lower cradle-to-gate emissions and manufacturing cost, with sustainability hotspots associated to hazardous methanol input and energy-intensive distillations. 2030 Agenda analysis also outlines palm-oil-to-biodiesel as best for 5 out of 10 Sustainable Development Goals linked to the reduced indicator set.

Spotlight on the Life Cycle of Acrylamide-Based Polymers Supporting Reductions in Environmental Footprint: Review and Recent Advances.

Humankind is facing a climate and energy crisis which demands global and prompt actions to minimize the negative impacts on the environment and on the lives of millions of people. Among all the disciplines which have an important role to play, chemistry has a chance to rethink the way molecules are made and find innovations to decrease the overall anthropic footprint on the environment. In this paper, we will provide a review of the existing knowledge but also recent advances on the manufacturing and end uses of acrylamide-based polymers following the "green chemistry" concept and 100 years after the revolutionary publication of Staudinger on macromolecules. After a review of raw material sourcing options (fossil derivatives vs. biobased), we will discuss the improvements in monomer manufacturing followed by a second part dealing with polymer manufacturing processes and the paths followed to reduce energy consumption and CO2 emissions. In the following section, we will see how the polyacrylamides help reduce the environmental footprint of end users in various fields such as agriculture or wastewater treatment and discuss in more detail the fate of these molecules in the environment by looking at the existing literature, the regulations in place and the procedures used to assess the overall biodegradability. In the last section, we will review macromolecular engineering principles which could help enhance the degradability of said polymers when they reach the end of their life cycle.

α-Chitin dissolution, N-deacetylation and valorization in deep eutectic solvents.

Chitin displays a highly rigid structure due to the vast intra- and intermolecular hydrogen bonding, thus hindering its dissolution and deacetylation using most solvents. Deep eutectic solvents (DESs) are special and environmentally friendly solvents composed of a hydrogen bond acceptor and a hydrogen bond donor. This allows them to dissolve chitin by disturbing its natural hydrogen bonding while establishing new bonds, hence turning the polymer more susceptible to solvents. Therefore, four distinct DESs (choline chloride-lactic acid ([Ch]Cl:LA), choline chloride:oxalic acid ([Ch]Cl:OA), choline chloride:urea ([Ch]Cl:U) and betaine-glycerol (Bet:G)) were applied in chitin dissolution, being the most performant ones further applied in its homogenous N-deacetylation with NaOH. In this work, a milder and more biocompatible approach was carried out by using 30 wt% NaOH at 80°C, instead of the typical ≥40 wt% NaOH at temperatures ≥100°C. Herein, the reaction process took up to 18 hours, being the results analyzed through ATR-FTIR. Chitin was converted into chitosan with a 70-80% degree of deacetylation (DDA) in a short period while using homogenous conditions. These promising results provide the first proof of concept of the ability of Bet:G and [Ch]Cl:LA-based DESs to be used as a greener approach for the chitin homogeneous N-deacetylation.

Unraveling the potential of non-thermal ultrasonic contact drying for enhanced functional and structural attributes of pea protein isolates: A comparative study with spray and freeze-drying methods.

The challenge of preserving the quality of thermal-sensitive polymeric materials specifically proteins during a thermal drying process has been a subject of ongoing concern. To address this issue, we investigated the use of ultrasound contact drying (USD) under non-thermal conditions to produce functionalized pea protein powders. The study extensively examined functional and physicochemical properties of pea protein isolate (PPI) in powder forms obtained through three drying methods: USD (30 °C), spray drying (SD), and freeze drying (FD). Additionally, physical attributes such as powder flowability and color, along with morphological properties, were thoroughly studied. The results indicated that the innovative USD method produced powders of comparable quality to FD and significantly outperformed SD. Notably, the USD-PPI exhibited higher solubility across all pH levels compared to both FD-PPI and SD-PPI. Moreover, the USD-PPI samples demonstrated improved emulsifying and foaming properties, a higher percentage of random coil form (56.2 %), increased gel strength, and the highest bulk and tapped densities. Furthermore, the USD-PPI displayed a unique surface morphology with visible porosity and lumpiness. Overall, this study confirms the effectiveness of non-thermal ultrasound contact drying technology in producing superior functionalized plant protein powders, showing its potential in the fields of chemistry and sustainable materials processing.

Recombinant cellobiose dehydrogenase from Thermothelomyces thermophilus: Its functional characterization and applicability in cellobionic acid production.

The fungus Thermothelomyces thermophilus is a thermotolerant microorganism that has been explored as a reservoir for enzymes (hydrolytic enzymes and oxidoreductases). The functional analysis of a recombinant cellobiose dehydrogenase (MtCDHB) from T. thermophilus demonstrated a thermophilic behavior, an optimal pH in alkaline conditions for inter-domain electron transfer, and catalytic activity on cellooligosaccharides with different degree of polymerization. Its applicability was evaluated to the sustainable production of cellobionic acid (CBA), a potential pharmaceutical and cosmetic ingredient rarely commercialized. Dissolving pulp was used as a disaccharide source for MtCDHB. Initially, recombinant exoglucanases (MtCBHI and MtCBHII) from T. thermophilus hydrolyzed the dissolving pulp, resulting in 87% cellobiose yield, which was subsequently converted into CBA by MtCDHB, achieving a 66% CBA yield after 24 h. These findings highlight the potential of MtCDHB as a novel approach to obtaining CBA through the bioconversion of a plant-based source.

Interconnection between renewable energy technologies and water treatment processes.

The renewable-energy-based water-energy nexus is a promising approach that contributes to climate change mitigation. Increasing concerns on GHG emission and energy demand, policies have been implemented in many countries to make use of renewable energy as much as possible. Renewable energy technologies can be directly employed in desalination processes, including membrane-based (e.g., reverse osmosis (RO) and membrane distillation (MD)) and thermal-based (e.g., multistage flash distillation (MSF) and multieffect distillation (MED)) technologies. Although the production capacities of fossil-based desalination processes (RO, MD, and MED) are higher than those of renewable-energy-based desalination processes, most latter desalination processes have lower specific energy consumption than conventional processes, which may offer potential for the implementation of renewable energy sources. In addition to the direct application of renewable energy technology to desalination, biofuels can be produced by converting algal lipids obtained from the growth of algae, which are associated with wastewater bioremediation and nitrogen and phosphorus removal during wastewater treatment. Salinity gradient power can be harvested from brine originating from desalination plants and freshwater driven by pressure-retarded osmosis or reverse electrodialysis. This study provides an overview of these approaches and discusses their effectiveness. It not only offers insights into the potential of applying renewable energy technologies to various water treatment processes but also suggests future directions for scientists to further enhance the efficiency of renewable energy production processes for possible implementation.

A framework for early-stage sustainability assessment of innovation projects enabled by weighted sum multi-criteria decision analysis in the presence of uncertainty.

A two-level hierarchical framework for early-stage sustainability assessment (FESSA) amongst a set of alternatives applicable from the earliest stages of process or product development is introduced, and its use in combination with an improved method weighted-sum method multi-criteria decision analysis (WSM-MCDA) in the presence of uncertainty is presented through application to a case study based upon a real-world decision scenario from speciality polymer manufacture. The approach taken addresses the challenge faced by those responsible for innovation management in the manufacturing process industries to make simultaneously timely and rational decisions early in the innovation cycle when knowledge gaps and uncertainty about the options tend to be at their highest. The Computed Uncertainty Range Evaluations (CURE) WSM-MCDA method provides better discrimination than the existing Multiple Attribute Range Evaluations (MARE) method without the computational burden of generating heuristic outcome distributions via Monte-Carlo simulation.

This paper introduces a framework that teams can use to think systematically about the wide range of criteria which go into deciding whether a proposed innovation enhances sustainability or not and shows how an improved method for multiple-criteria decision analysis can be used to put it into practice with an example drawn from the speciality chemicals industry. Innovation in the manufacturing process industries requires decisions to be made. In individual projects, scientists and technical managers must decide which technology, materials, and equipment to use. Equally, those responsible for directing a portfolio of projects must choose which projects to prioritise. In either case, early decision making is desirable to avoid sinking time and money into dead-end projects, and to identify what further work is needed for projects with a future. The earlier you decide however, the harder it can be to obtain firm evidence (e.g. conclusive experimental data, fully validated costings, or life cycle impacts) upon which to base your decision. The growing societal expectation that sustainability criteria are factored into such decisions merely adds to the challenges faced by the decision maker. Decisions must be made upon the evidence that is available combined with the informed judgement of those with knowledge of the system under consideration. This is best approached as a facilitated, team-based activity where assertions, assumptions and interpolations or extrapolations from the limited data can be tested and challenged. A sound decision-making process needs a suitable computational method for turning this complex qualitative and semi-quantitative assessment into a clear output indicator of potential success or failure for the options under consideration. The method described in this paper addresses this need but, just as importantly, the methodology ensures that the thought process behind whatever decision is indicated is clearly and transparently documented for future reference.

Evaluating the catalytic effect of Fe@Fe2O3-modified granulated cork as an innovative heterogeneous catalyst in electro-fenton degradation of benzoquinone in different aqueous matrices.

This study investigated the potential of a novel biomass-derived cork as a suitable catalyst after its modification with Fe@Fe2O3 for in-situ application in heterogeneous electro-Fenton (HEF) process for benzoquinone (BQ) elimination from water. No attempts on the application of modified granulated cork (GC) as a suspended heterogeneous catalyst in the HEF process for water treatment have been published yet. GC was modified by sonification approach in a FeCl3 + NaBH4 solution to reduce the ferric ions to metallic iron in order to obtain Fe@Fe2O3-modified GC (Fe@Fe2O3/GC). Results clearly demonstrated that this catalyst exhibited excellent electrocatalytic properties, such as a high conductivity as well as relatively high redox current and possessed several active sites for water depollution applications. Using Fe@Fe2O3/GC as catalyst in HEF, 100% of BQ removal was achieved in synthetic solutions by applying 33.3 mA cm-2 after 120 min. Different experimental conditions were tested to determine that best possible conditions can be as follow: 50 mmol L-1 Na2SO4 and 10 mg L-1 of Fe@Fe2O3/GC catalyst using Pt/carbon-PTFE air diffusion cell by applying 33.3 mA cm-2. Nevertheless, when Fe@Fe2O3/GC was used in the HEF approach to depollute real water matrices, no complete BQ concentration was removal achieved after 300 min of treatment, achieving between 80 and 95% of effectiveness.

Metabolic engineering of Corynebacterium glutamicum for l-tyrosine production from glucose and xylose.

Microbial production of aromatic compounds is an attractive and sustainable biotechnological approach. With this motivation, here metabolic engineering of Corynebacterium glutamicum for l-tyrosine (l-Tyr) overproduction was attempted by pushing the carbon flux more towards l-Tyr. Translational start codon exchanges of prephenate dehydratase (pheA), anthranilate synthase (trpE), and phenylalanine aminotransferase (pat) genes revealed that reduced expression of pheA was the major contributor to increased l-Tyr titer while codon exchange in trpE was effective to a lower extent. Overexpression of aroE and qsuC, encoding shikimate dehydrogenase and 3-dehydroquinate dehydratase, respectively, and of dapC (cg1253), which is predicted to encode prephenate aminotransferase, were futile to increase l-Tyr titer. Similarly, deletion of the qsuABD gene cluster had also not enhanced titer. As for increasing precursor supply, deletion of ptsG of glucose uptake and overexpression of inositol permease (iolT2) and glucokinase (glcK) were not effective, but with utilization of xylose, enabled by overexpression of xylose isomerase (xylA) and xylulokinase (xylB), titer improved. Highest l-Tyr titer using the construct was 3.1 g/L on glucose and 3.6 g/L on a 1:3 (w/v) mixture of glucose and xylose. This result displays the potential of the constructed strain to produce l-Tyr from lignocellulosic renewable carbon sources.

Non-thermal ultrasonic contact drying of pea protein isolate suspensions: Effects on physicochemical and functional properties.

Pea protein isolate (PPI) is a popular plant-based ingredient, typically produced through alkaline-isoelectric precipitation and thermal drying. However, high temperatures and long drying times encountered in thermal drying can denature PPI and cause loss of functionality. This study investigated the use of an innovative ultrasonic dryer (US-D) at 30 °C for drying PPI suspensions, compared to conventional hot air drying (HA-D) at 60 °C. US-D led to an increase in the drying rate and correspondingly reduced the drying time by 55 %, when compared to HA-D. The average effective moisture diffusivity in the US-D process was 325 % higher than that in the HA-D process. The resulting PPI exhibited higher solubility, emulsification, and foaming properties than HA-D PPI, with a unique surface morphology and higher surface area. This study demonstrated that drying with acoustic energy is a promising approach for producing dried plant protein ingredients with improved functional properties, reduced processing time, and increased production efficiency.

Precise Modeling of the Particle Size Distribution in Emulsion Polymerization: Numerical and Experimental Studies for Model Validation under Ab Initio Conditions.

The particle size distribution (PSD) in emulsion polymerization (EP) has been modeled in the past using either the pseudo bulk (PB) or the 0-1/0-1-2 approaches. There is some controversy on the proper type of model to be used to simulate the experimental PSDs, which are apparently broader than the theoretical ones. Additionally, the numerical technique employed to solve the model equations, involving hyperbolic partial differential equations (PDEs) with moving and possibly steep fronts, has to be precise and robust, which is not a trivial matter. A deterministic kinetic model for the PSD evolution of ab initio EP of vinyl monomers was developed to investigate these issues. The model considers three phases, micellar nucleation, and particles that can contain n≥0 radicals. Finite volume (FV) and weighted-residual methods are used to solve the system of PDEs and compared; their limitations are also identified. The model was validated by comparing predictions with data of monomer conversion and PSD for the batch emulsion homopolymerization of styrene (Sty) and methyl methacrylate (MMA) using sodium dodecyl sulfate (SDS)/potassium persulfate (KPS) at 60 °C, as well as the copolymerization of Sty-MMA (50/50; mol/mol) at 50 and 60 °C. It is concluded that the PB model has a structural problem when attempting to adequately represent PSDs with steep fronts, so its use is discouraged. On the other hand, there is no generalized evidence of the need to add a stochastic term to enhance the PSD prediction of EP deterministic models.

Potential of major by-products from non-ferrous metal industries for CO2 emission reduction by mineral carbonation: a review.

By-products from the non-ferrous industry are an environmental problem; however, their economic value is high if utilized elsewhere. For example, by-products that contain alkaline compounds can potentially sequestrate CO2 through the mineral carbonation process. This review discusses the potential of these by-products for CO2 reduction through mineral carbonation. The main by-products that are discussed are red mud from the alumina/aluminum industry and metallurgical slag from the copper, zinc, lead, and ferronickel industries. This review summarizes the CO2 equivalent emissions generated by non-ferrous industries and various data about by-products from non-ferrous industries, such as their production quantities, mineralogy, and chemical composition. In terms of production quantities, by-products of non-ferrous industries are often more abundant than the main products (metals). In terms of mineralogy, by-products from the non-ferrous industry are silicate minerals. Nevertheless, non-ferrous industrial by-products have a relatively high content of alkaline compounds, which makes them potential feedstock for mineral carbonation. Theoretically, considering their maximum sequestration capacities (based on their oxide compositions and estimated masses), these by-products could be used in mineral carbonation to reduce CO2 emissions. In addition, this review attempts to identify the difficulties encountered during the use of by-products from non-ferrous industries for mineral carbonation. This review estimated that the total CO2 emissions from the non-ferrous industries could be reduced by up to 9-25%. This study will serve as an important reference, guiding future studies related to the mineral carbonation of by-products from non-ferrous industries.

The co-conversion of methane and mixtures of volatile fatty acids into poly(3-hydroxybutyrate-co-3-hydroxyvalerate) expands the potential of an integrated biorefinery.

In this work, the potential of Methylocystis hirsuta to simultaneously use methane and volatile fatty acids mixtures for triggering PHBV accumulation was assessed for the first time batchwise. Biotic controls carried out with CH4 alone confirmed the inability of Methylocystis hirsuta to produce PHBV and achieved 71.2 ± 7 g m-3d-1 of PHB. Pure valeric acid and two synthetic mixtures simulating VFAs effluents from the anaerobic digestion of food waste at 35 °C (M1) and 55 °C (M2) were supplied to promote 3-HV inclusion. Results showed that pure valeric acid supported the highest polymer yields of 105.8 ± 9 g m-3d-1 (3-HB:3-HV=70:30). M1 mixtures led to a maximum of 103 ± 4 g m-3d-1 of PHBV (3-HB:3-HV=85:15), while M2 mixtures, which did not include valeric acid, showed no PHV synthesis. This suggested that the synthesis of PHBV from VFAs effluents depends on the composition of the mixtures, which can be tuned during the anaerobic digestion process.

Thin Film Biocomposite Membrane for Forward Osmosis Supported by Eggshell Membrane.

There is a general drive to adopt highly porous and less tortuous supports for forward osmosis (FO) membranes to reduce internal concentration polarization (ICP), which regulates the osmotic water permeation. As an abundant waste material, eggshell membrane (ESM) has a highly porous and fibrous structure that meets the requirements for FO membrane substrates. In this study, a polyamide-based biocomposite FO membrane was fabricated by exploiting ESM as a membrane support. The polyamide layer was deposited by the interfacial polymerization technique and the composite membrane exhibited osmotically driven water flux. Further, biocomposite FO membranes were developed by surface coating with GO for stable formation of the polyamide layer. Finally, the osmotic water flux of the eggshell composite membrane with a low structural parameter (~138 µm) reached 46.19 L m-2 h-1 in FO mode using 2 M NaCl draw solution.

Novel sustainable metallic powder production process with water used as milling medium.

Today, Fe-Al intermetallic compounds are receiving a great interest from the mechanical, aerospace, and biomedical industries. A novel production process for Fe-Al intermetallic powders based on the generation of metallic tapes by rapid solidification and disintegration by water vapor was proposed. In this research work, a comparison is made between the energy required to manufacture of Fe-Al powder using the aforementioned process and one of the most commonly used manufacturing processes within the industry such as mechanical alloying. In addition, some other benefits of the proposed manufacturing process are analyzed. To carry out this comparison, the theoretical equations that take into account the most important variables involved during the process such as the type of material and hardness, the initial and final particle size, the grinding stages and the heating of the treatment powder were considered. In the case of calculating the energy required for the new proposed process, the two main stages were considered such as (1) the production of FeAl metal tape and (2) the subsequent transformation of the tape into powder by means of injection water vapor. For the first stage, the CASTRIP process is considered, and for the second stage, the energy required for the generation steam. Although the calculations may have certain limitations, it is obvious that the energy required to Fe-Al powder production using the new process is much lower than that required by mechanical alloying, resulting in at least three orders of magnitude lower (2.75 × 106 versus 2.206 × 109 kJ/ton). This lower energy implies considerable economic savings in the production process. On the other hand, when using water as a grinding medium during the process, it results in less environmental and acoustic pollution, less manipulation risks for humans and finally, no harmful agents or additives are used, making the proposed process sustainable.

Cu-catalyzed Synthesis of Quinolines by Dehydrogenative Reaction of 2-Aminobenzyl Alcohol and Ketones: A Combined Experimental and Computational Study.

Quinoline derivatives are important moieties in bioactive molecules and advanced materials. However, an efficient strategy to synthesize quinoline derivatives remains challenging. Herein, we describe an efficient and practical method for the synthesis of quinolines by Cu-catalyzed cyclization of 2-amino benzyl alcohol with ketones (or secondary alcohols) via an acceptorless dehydrogenation pathway. Interestingly, a range of highly functionalized quinolines is prepared in good yields using low catalyst loading under relatively mild conditions. Furthermore, density functional theory (DFT) calculations are carried out to investigate mechanistic insights for the acceptorless dehydrogenation pathway.

Spent Yeast Valorization for Food Applications: Effect of Different Extraction Methodologies.

Over the years, synthetic biology has been growing with the use of engineered yeast strains for the production of sustainable ingredients to meet global healthcare, agriculture, manufacturing and environmental challenges. However, as seen from the brewing industry perspective, these processes generate a substantial amount of spent yeast that contains high nutritional value related to its high protein content, showing its potential to be used as an alternative protein source. Taking into account the rising demand for protein because of the growth in the global population, the present study aims to produce peptide-rich extracts by different potentially scalable and sustainable methodologies in a circular economy approach for the food and nutraceutical industries. The results demonstrated that extraction from genetically modified strains allowed the production of extracts with an excellent nutritional profile and low molecular weight peptides. Furthermore, autolysis was shown to be a potential sustainable approach for this production, though other green metrics need to be explored in order to establish this process at an industrial level.

Unprecedented Mechanochemical Synthesis and Heterogenization of a C-Scorpionate Au(III) Catalyst for Microwave-Assisted Biomass Valorization.

The transformation of biomass, a carbon resource presenting a huge potential to produce valuable chemicals, requires the search for sustainable catalytic routes. This work proposes the microwave-assisted oxidation of biomass -derived substrates, such as glycerol and the furfural derivatives 5-(hydroxymethyl)furfural (HMF) and 5-hydroxymethyl-2-furancarboxylic acid (HFCA), using the C-scorpionate dichloro-gold(III) complex [AuCl2(κ2-Tpm)]Cl (Tpm = HCpz3; pz = pyrazol-1-yl) as a catalyst, as prepared and supported on graphene, in solvent-free conditions. The unprecedented application of a mechanochemical procedure (in a planetary ball mill, in solid state) to synthesize a C-scorpionate complex, the [AuCl2(κ2-Tpm)]Cl, is disclosed. The immobilization of [AuCl2(κ2-Tpm)]Cl on graphene was performed using different methods, including some (e.g., microwave irradiation and liquid assisted grinding) for the first time. The structural properties and the performance of the prepared catalytic materials are presented and discussed.