Fine-Tuning of Ni/NiO over H-NbOx for Enhanced Eugenol Hydrogenation through Enhanced Oxygen Vacancies and Synergistic Participation of Active Sites.

The hydrogenation of lignin-derived phenolics to produce valuable chemicals is a promising but challenging task. This study successfully demonstrates the use of sustainable transition metal-based catalysts to hydrogenate lignin-derived phenolics. A defect-induced oxygen vacancy containing H-NbOx prepared from commercial Nb2O5 was employed as a catalyst. H-NbOx exhibited higher oxygen vacancies (158.21 µmol/g) than commercial Nb2O5 (39.01 µmol/g), evaluated from O2-TPD. Upon supporting 10 wt % Ni, a Ni/NiO interface was formed over H-NbOx, which was intrinsically active for the hydrogenation of phenolics. 10Ni/H-NbOx exhibited a two-fold increase in activity than 10Ni/Nb2O5, achieving >99% eugenol conversion and affording ∼94% 4-propyl cyclohexanol selectivity, wherein ∼63% eugenol conversion and ∼73% 4-propyl cyclohexanol selectivity were obtained over 10Ni/Nb2O5. The Ni/NiO formation was confirmed by X-ray photoelectron spectroscopy, HR-TEM, and H2-TPR analysis, while the oxygen vacancies were verified by Raman spectroscopy and O2-TPD analysis. The resulting interface enhanced the synergy between Ni and H-NbOx and facilitated hydrogen dissociation, confirmed by H2-TPD. Remarkably, 10Ni/H-NbOx maintained its catalytic activity for five tested cycles and demonstrated exceptional activity with various phenolics. Our findings highlight the potential of a sustainable transition metal catalyst for the hydrogenation of lignin-derived phenolic compounds, which could pave the path to producing valuable chemicals in an environmentally friendly manner.

Moving the stakeholder journey forward.

Though the customer journey (CJ) is gaining traction, its limited customer focus overlooks the dynamics characterizing other stakeholders' (e.g., employees'/suppliers') journeys, thus calling for an extension to the stakeholder journey (SJ). Addressing this gap, we advance the SJ, which covers any stakeholder's journey with the firm. We argue that firms' consideration of the SJ, defined as a stakeholder's trajectory of role-related touchpoints and activities, enacted through stakeholder engagement, that collectively shape the stakeholder experience with the firm, enhances their stakeholder relationship management and performance outcomes. We also view the SJ in a network of intersecting journeys that are characterized by interdependence theory's structural tenets of stakeholder control, covariation of interest, mutuality of dependence, information availability, and temporal journey structure, which we view to impact stakeholders' journey-based engagement and experience, as formalized in a set of Propositions. We conclude with theoretical (e.g., further research) and practical (e.g., SJ design/management) implications.

Cu-Ce Bimetallic Metal-Organic Framework-Derived, Oxygen Vacancy-Boosted Visible Light-Active Cu2O-CeO2/C Heterojunction: An Efficient Photocatalyst for the Sonogashira Coupling Reaction.

The development of an economical transition metal-based catalyst for photocatalytic carbon-carbon coupling reactions is aspiring. Herein, a Cu-Ce metal-organic framework (MOF) was synthesized and carbonized to produce bimetallic Cu2O-CeO2/C, which was utilized in the Sonogashira cross-coupling reaction. The defects and oxygen vacancies in the catalyst were characterized by X-ray photoelectron spectroscopy and Raman spectroscopy, while the nature of Cu was characterized by H2-TPR analysis. The defect-induced MOF-derived Cu-Ce heterojunction created more oxygen vacancies (OV) in CeO2, revealing the high photocatalytic activity. The Cu-Ce heterojunction (Cu2O-CeO2/C) formed a Cu(I)-phenylacetylide active complex and exhibited higher catalytic activity for the visible light-induced Sonogashira cross-coupling reaction. 25%Cu2O-CeO2/C offered 93.8% phenylacetylene conversion with a 94.2% Sonogashira product selectivity by using household light-emitting diodes. No discernible activity loss was observed from the recycling of the catalyst. Based on catalytic activity, control reactions, and physicochemical and optoelectronic characterization, the structure-activity relationship was established and a reaction mechanism was proposed. Replacement of the costly Pd metal-based catalyst with a cheap Cu2O-CeO2-based catalyst for the synthesis of commercially important compounds with a sustainable visible light-induced catalytic process will be highly attractive to chemists and industrialists.

Oxygen Vacancy-Mediated Z-Scheme Charge Transfer in a 2D/1D B-Doped g-C3N4/rGO/TiO2 Heterojunction Visible Light-Driven Photocatalyst for Simultaneous/Efficient Oxygen Reduction Reaction and Alcohol Oxidation.

Hydrogen peroxide (H2O2) is a powerful oxidant that directly or indirectly oxidizes many organic and inorganic contaminants. The photocatalytic generation of H2O2 is achieved by using a semiconductor photocatalyst in the presence of alcohol as a proton source. Herein, we have synthesized oxygen vacancy (Ov)-mediated TiO2/B-doped g-C3N4/rGO (TBCN@rGO) ternary heterostructures by a simple hydrothermal technique. Several characterization techniques were employed to explore the existence of oxygen vacancies in the crystal structure and investigate their impact on the optoelectronic properties of the catalyst. Oxygen vacancies offered additional sites for adsorbing molecular oxygen, activating alcohols, and facilitating electron migration from TBCN@rGO to the surface-adsorbed O2. The defect creation (oxygen vacancy) and Z-scheme mechanistic pathways create a suitable platform for generating H2O2 by two-electron reduction processes. The optimized catalyst showed the highest photocatalytic H2O2 evolution rate of 172 µmol/h, which is 1.9 and 2.5 times greater than that of TBCN and BCN, respectively. The photocatalytic oxidation of various lignocellulose-derived alcohols (such as furfural alcohol and vanillyl alcohol) and benzyl alcohol was also achieved. Photocatalytic activity data, physicochemical and optoelectronic features, and trapping experiments were conducted to elucidate the structure-activity relationships. The TBCN@rGO acts as a multifunctional Z-scheme photocatalyst having an oxygen vacancy, modulates surface acidity-basicity required for the adsorption and activation of the reactant molecules, and displays excellent photocatalytic performance due to the formation of a large number of active surface sites, increased electrical conductivity, improved charge transfer properties, outstanding photostability, and reusability. The present study establishes a unique strategy for improving H2O2 generation and alcohol oxidation activity and also provides insights into the significance of a surface vacancy in the semiconductor photocatalyst.

Comprehensive Understanding of the Eco-Friendly Synthesis of Zeolites: Needs of 21st Century Sustainable Chemical Industries.

Zeolites have taken a leading position in petrochemical, fine, and bulk chemical industries due to their porous architecture, pore sizes, tunable acidity, and thermal stability. Various strategies of zeolites preparation, including template-free, solvent-free, and toxic mineral-free strategies are summarized. Moreover, the zeolite synthesis using naturally occurring minerals and sustainable natural templates is also discussed, which involves the synthesis of nanocrystalline zeolites of different framework structures using plant-based natural templates and biomass-derived renewable chemicals. Overall this personal account provides the fundamentals of various sustainable synthetic strategies reported in the literature for the synthesis of zeolites with suitable examples that will be useful for the students and will motivate experienced researchers to develop various novel sustainable methods for the synthesis of zeolites and other inorganic materials of industrial relevance.

Electrochemical Sensor Platforms Based on Nanostructured Metal Oxides, and Zeolite-Based Materials.

Electrochemical sensors have drawn significant attention over the last couple of decades because of their ability to improve detection of organic and inorganic analytes found in the field of biotechnology, environmental sciences, medicine, and food quality control. This personal account summarizes the state-of-art research carried out in the construction and evaluation of nanostructured metal oxides and zeolite based electrochemical sensors. Metal oxides and zeolite-based nanomaterials have many unique and extraordinary properties such as tunable redox activity, surface functionalization ability, optimum conductivity, large surface area, biocompatibility and so forth. In this personal account, the current advances in electrochemical sensor applications of metal oxides, zeolite-based nanomaterials, and their nanocomposites are described for the single and simultaneous determination of organic & inorganic contaminants present in water bodies, physiological bio-molecules present in human blood & urine samples, and organic contaminants present in food materials.Moreover, concluding section focuses discussion on the future developments and applications of these materials in various emerging technologies.

ZSM-5 zeolite nanosheets with improved catalytic activity synthesized using a new class of structure-directing agents.

A new series of multiquaternary ammonium structure-directing agents, based on 1,4-diazabicyclo[2.2.2]octane, was prepared. ZSM-5 zeolites with nanosheet morphology (10 nm crystal thickness) were synthesized under hydrothermal conditions using multiquaternary ammonium surfactants as the zeolite structure-generating agents. Both wide-angle and small-angle diffraction patterns were obtained using only a suitable structure-directing agent under a specific zeolite synthesis composition. A mechanism of zeolite formation is proposed based on the results obtained from various physicochemical characterizations. ZSM-5 materials were investigated in catalytic reactions requiring medium to strong acidity, which are important for the synthesis of a wide range of industrially important fine and specialty chemicals. The catalytic activity of ZSM-5 materials was compared with that of the conventional ZSM-5 and amorphous mesoporous aluminosilicate Al-MCM-41. The synthesis strategy of the present investigation using the new series of structure-directing agents could be extended for the synthesis of other related zeolites or other porous materials in the future. Zeolite with a structural feature as small as the size of a unit cell (5-10 nm) with hierarchically ordered porous structure would be very promising for catalysis.

Simultaneous determination of ascorbic acid, dopamine, uric acid, and tryptophan by nanocrystalline ZSM-5 modified electrodes.

Nanocrystalline ZSM-5 was prepared by using propyltriethoxysilane as an additive in the conventional ZSM-5 synthesis composition. Materials were characterized by a complementary combination of X-ray diffraction, nitrogen sorption, and Scanning electron microscopy. Transition metal ion exchanged nanocrystalline ZSM-5 (M-Nano-ZSM-5, where M = Cu2+, Ni2+, Co2+, Fe2+, and Mn2+) modified electrodes were constructed for the simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA), and tryptophan (Trp). Electrochemical studies were carried out by using cyclic voltammetry, linear sweep voltammetry, and chronoamperometry in buffer solution at pH 3.5. Fe-Nano-ZSM-5 modified electrode exhibited excellent electrocatalytic activity with well-separated oxidation peaks towards AA, DA, UA, and Trp in their simultaneous determination. Among the M-Nano-ZSM-5 and transition metal ion-exchanged ZSM-5 (M-ZSM-5) materials investigated in this study, Fe-Nano-ZSM-5 exhibited the highest catalytic activities towards the oxidation of AA, DA, UA, and Trp with good stability, sensitivity, and selectivity. The analytical performance of this sensor was demonstrated for the simultaneous determination of AA, DA, UA, and Trp in blood serum and UA concentration in urine samples.

Management of complicated ureteroceles: Different modalities of treatment and long-term outcome.

The presentation and management of ureterocele has been rarely reported from India and is limited to an odd case report. They can be detected antenatally, may have incidental diagnosis or present with consequences of obstructive uropathy. They always present with secondary complications in adulthood, if the diagnosis and treatment is missed in early years of life. The natural history may be particularly disastrous in cases of bilateral obstructing ureterocele. The complications secondary to obstructive ureterocele can be urinary retention, pyonephrosis, urosepsis, stones and even chronic renal failure. Each of these patients needs an individualized treatment plan. In the period 2003-2013, we managed 36 consecutive patients with varied presentation of this entity. All were managed on the basis of a fixed protocol of investigation and operative intervention. Ultrasound, micturating cystourethrogram, isotope renogram were done preoperatively in all the babies. Those with asymptomatic, unobstructed ureteroceles were left without any intervention. Simple or complex intravesical ureteroceles underwent examination under anesthesia and endoscopic deroofing and DJ stenting for 3 weeks. Of a total of 36 children, 6 were presented with acute complications of ureterocele. They have been managed on an individualized optimum management plan. Their management approach with follow-up is being reported as there is no previous reported series on ureterocele in children from our country.

Robotic augmentation ileocystoplasty with bilateral ureteric reimplantation in a young child with neuropathic bladder.

Neuropathic bladder in children is most commonly secondary to spina bifida. The management starts early in life. The modalities of treatment vary depending on the severity of the symptoms. A proportion of children inspite of adequate medical management need augmentation ileocystoplasty later in life. The open surgery has proven safety and success over many decades. Earlier attempts to perform augmentation cystoplasty by the laparoscopic approach were limited by steep learning curve, long operating times, and technical difficulties in intracorporeal anastomosis. The emergence of robotic technology has revived the interest in minimally invasive approach for complex pediatric urological reconstructions. In the recent times, there has been only one reported case report and small series of pediatric robotic augmentation cystoplasty from Chicago. We report the first minimally invasive robotic reconstruction in a child with neuropathic bladder and early renal decompensation despite appropriate medical treatment, from our country.

Effect of dehusking and cooking on protein and dietary fibre of different genotypes of desi, kabuli and green type chickpeas (Cicer arietinum).

Dehusking and cooking are essential and important component of processing of chickpea to enhance the digestibility of essential nutrients of grains. Protein and dietary fibres are important due to their role in lowering plasma cholesterol and other health advantages. Changes during dehusking and dehusking followed by cooking on soluble protein, cellulose, hemicellulose, lignin and pectin contents of four genotypes of desi type (BG 256, JG 74, KWR 108 and DCP 92-3), four genotypes of kabuli type (BG 1053, KAK 2, JKG 1 and L 550) and two genotypes of green type (Sadabahar and BDG 112) of chickpeas (Cicer arietinum) were studied. The cellulose, hemicellulose and lignin of grain decreased to an extent of 21.6 %, 29.6 % and 27.3 % respectively on dehusking, whereas pectin recorded an increase of 26.2 % on dehusking. The cooking of dehusked grain registered a marginal increase in cellulose, lignin and pectin, but a decrease in hemicellulose content. The soluble protein recorded an increase of 21.3 % on dehusking and 26.6 % increase on cooking, as compared to unprocessed grain.

Introduction to Photocatalytic Materials for Clean Energy, Renewable Chemicals production, and Sustainable Catalysis.

Professor Rajeev Ahuja & Professor Rajendra Srivastava introduce the Nanoscale Advances themed collection on Photocatalytic Materials for Clean Energy, Renewable Chemicals production, and Sustainable Catalysis.

Oxidative Cleavage of α-O-4, ß-O-4, and 4-O-5 Linkages in Lignin Model Compounds Over P, N Co-Doped Carbon Catalyst: A Metal-Free Approach.

Developing efficient metal-free catalysts for lignin valorization is essential but challenging. In this study, a cost-effective strategy is employed to synthesize a P, N co-doped carbon catalyst through hydrothermal and carbonization processes. This catalyst effectively cleaved α-O-4, ß-O-4, and 4-O-5 lignin linkages, as demonstrated with model compounds. Various catalysts were prepared at different carbonization temperatures and thoroughly characterized using techniques such as XRD, RAMAN, FTIR, XPS, NH3-TPD, and HRTEM. Attributed to higher acidity, the P5NC-500 catalyst exhibited the best catalytic activity, employing H2O2 as the oxidant in water. Additionally, this metal-free technique efficiently converted simulated lignin bio-oil, containing all three linkages, into valuable monomers. Density Functional Theory calculations provided insight into the reaction mechanism, suggesting substrate and oxidant activation by P-O-H sites in the P5NC-500, and by N-C-O-H in the CN catalyst. Moreover, the catalyst's recyclability and water utilization enhance its environmental compatibility, offering a highly sustainable approach to lignin valorization with potential applications in various industries.

Recycling Valuable Phenol from Polycarbonate Plastic Waste via Direct Depolymerization and Csp2-Csp3 Bond Cleavage Under Mild Conditions.

Upcycling plastic waste into commodity chemicals is recognized as an environmentally benign solution and beneficial for the sustained growth of humanity. Nevertheless, transition metal-free catalysts and energy-efficient conditions pose significant challenges due to the robust mechanical properties of plastics. Here, a strategy for selective production of phenol by upcycling polycarbonate waste via direct depolymerization and Csp2-Csp3 bond cleavage in an aqueous medium under mild conditions is reported. The commercial zeolites efficiently catalyze the depolymerization, Csp2-Csp3 bond hydrolysis, and direct Csp2-Csp3 bond scission at Cα of PC. Among all evaluated zeolites, HY (Si/Al=15) showed excellent catalytic performance, attributed to the ~75% yield of phenol and ~15% of acetone. The approach also employs different municipal waste PC for upcycling. Studies reveal that HY (15) exhibits high catalytic efficiency and phenol yield due to its optimum acid sites and textual properties. A scale-up experiment demonstrated that 3.1 g of phenol was produced from 5.0 g of PC, and the mass balance was 90%. A combination of control experiments, NMR analysis, and DFT studies proposed the reaction pathway. Our findings present a sustainable avenue for upcycling PC waste and offer a new way to produce phenol, contributing to the advancement of a circular economy.

A Detailed Assessment of Variations of Ethmoid Roof, Olfactory Fossa, and Anterior Ethmoidal Artery on CT Scan of Paranasal Sinuses of 200 Patients.

To study and analyse the variations in ethmoid roof anatomy and estimate the anatomical location and variations of AEA on CT scans. The study is conducted on 200 patients for detailed analysis of the olfactory fossa (OF) depth, supraorbital pneumatisation, and AEA location and distance from the skull base. In our study, Keros type II was predominant type seen followed by type I. Asymmetry was noted in 32/200 subjects (16%). The anterior ethmoidal artery (AEA) canal was seen in 341/400 sides (85.2%). We found Keros type II was the most common type in our study. We also found grade I anterior ethmoidal artery as the most common variant and the dangerous grade III anterior ethmoidal artery was least common type found in this study, and there was a significant association of Keros type II with increasing anterior ethmoidal artery grading.

Larvicidal isoxazoles: Synthesis and their effective susceptibility towards Aedes aegypti larvae.

Twenty 3,5-disubstituted isoxazoles have been synthesized and tested against fourth instar Aedes aegypti larvae. In the synthesis of title compounds, modifications have been made in the C-5 side-chain with a view to test their larvicidal activity. These isoxazoles have been obtained by 1,3-dipolar cycloaddition of arylnitrile oxides to terminal alkynes which furnished the desired products in 20% to 79% yields. A comparative study of the larvicidal activity between 3-(3-aryl-isoxazol-5-yl)-propan-1-ols and 3-(3-aryl-isoxazol-5-yl)-propionic acids clearly demonstrated that the latter compounds possess much better larvicidal activity than the former. We also tested two esters, viz., methyl 3-[3-(phenyl)-isoxazole-5-yl] propionate and methyl 3-[3-(4-chlorophenyl)-isoxazole-5-yl] propionate, where the latter presented an excellent larvicidal profile.

Effect of soaking and cooking on dietary fibre components of different type of chickpea genotypes.

Processing is an important and essential component to enhance the digestibility of essential nutrients of grains. Dietary fibres play an important role in bringing health advantages in chickpea and help in lowering plasma cholesterol. Changes during soaking and soaking followed by cooking on cellulose, hemicellulose, lignin and pectin contents of four genotypes of desi type (KWR 108, JG 74, DCP 92-3 and BG 256), four genotypes of kabuli types (KAK 2, JKG 1, BG 1053, and L 550) and two genotypes of green seed type (BGD 112 and Sadabahar) of chickpeas (Cicer arietinum, L.) was studied. Cellulose, lignin and pectin increased during soaking and cooking, whereas hemicellulose increased during soaking but decreased drastically during cooking. Cellulose recorded an overall increase of 40% during cooking, followed by 15.7% and 15.2% increase in pectin and lignin, respectively during cooking of chickpea grain. Hemicellulose, on the contrary showed a decrease of 26.8% during cooking.

Influence of Additives and Growth Inhibitors in Improving the Physicochemical Properties of Silicoaluminophosphate Molecular Sieve, SAPO-11.

Silicoalumiophosphates (SAPOs) are microporous crystalline materials extensively utilized as adsorbents and catalysts. The present work utilized two strategies to synthesize nanocrystalline SAPO-11. The first strategy involves a surfactant as a mesoporogen to reduce the crystallite size and increase the surface area for the materials synthesized at 200 °C in 2 days. In the second strategy, the synthesis temperature and time were significantly reduced to 160 °C and 3 h using propylene oxide as a pH accelerator. The reduction in the particle size and the improvement in the surface area were achieved using propyltriethoxysilane, which inhibited the growth of SAPO-11 particles. The materials were thoroughly characterized using XRD, N2 -sorption, FTIR, pyridine-adsorbed FTIR, electron microscopy, XPS, and NMR. The surfactant-assisted synthesis formed a nanorod morphology with a large external and BET surface area. The low-temperature synthesis involving silane as a growth inhibitor and propylene oxide as a pH modulator demonstrated a rectangular nanoplatelet morphology with a large surface area. The synthesis was scaled up to 10 g with no change in the experimental parameters. A synthesis strategy facilitating nuclei formation and retarding the growth of particle size will attract academia and industrial researchers to utilize these strategies for the manufacturing of zeolites of different frameworks on a large scale.

Reductive Oligomerization of Nitroaniline Catalyzed by Fe3O4 Spheres Decorated with Group 11 Metal Nanoparticles.

The present work demonstrates a simple and sustainable method for forming azo oligomers from low-value compounds such as nitroaniline. The reductive oligomerization of 4-nitroaniline was achieved via azo bonding using nanometric Fe3O4 spheres doped with metallic nanoparticles (Cu NPs, Ag NPs, and Au NPs), which were characterized by different analytical methods. The magnetic saturation (M s) of the samples showed that they are magnetically recoverable from aqueous environments. The effective reduction of nitroaniline followed pseudo-first-order kinetics, reaching a maximum conversion of about 97%. Fe3O4-Au is the best catalyst, its a reaction rate (k Fe3O4-Au = 0.416 mM L-1 min-1) is about 20 times higher than that of bare Fe3O4 (k Fe3O4 = 0.018 mM L-1 min-1). The formation of the two main products was determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS), evidencing the effective oligomerization of NA through N = N azo linkage. It is consistent with the total carbon balance and the structural analysis by density functional theory (DFT)-based total energy. The first product, a six-unit azo oligomer, was formed at the beginning of the reaction through a shorter, two-unit molecule. The nitroaniline reduction is controllable and thermodynamically viable, as shown in the computational studies.

Improving the hydrodeoxygenation activity of vanillin and its homologous compounds by employing MoO3-incorporated Co-BTC MOF-derived MoCoOx@C.

Lignin-derived aryl ethers and vanillin are essential platform chemicals that fulfil the demands for renewable aromatic compounds. Herein, an efficient heterogeneous catalyst is reported for reforming vanillin via a selective hydrodeoxygenation route to 2-methoxy-4-methyl phenol (MMP), a precursor to medicinal, food, and petrochemical industries. A series of MoCoOx@C catalysts were synthesized by decorating the Co-BTC MOF with different contents of MoO3 rods, followed by carbonization. Among these catalysts, MoCoOx@C-2 afforded ∼99% vanillin conversion and ∼99% MMP selectivity at 150 °C in 1.5 h in an aqueous medium. In contrast, CoOx@C afforded ∼75% vanillin conversion and ∼85% MMP selectivity. Detailed catalyst characterization revealed that CoOx and Co2Mo3O8 were the active species contributing to the higher activity of MoCoOx@C-2. The excellent H2-adsorption characteristics and acidity of MoCoOx@C-2 were beneficial to the hydrodeoxygenation of vanillin and other homologous compounds. The DFT adsorption energy calculations suggested the favourable interactions of vanillin and vanillyl alcohol with the Co2Mo3O8 sites in MoCoOx@C-2. The catalyst could be efficiently recycled 5 times, with a negligible loss in activity after the 5th cycle. These findings provide a systematic explication of the active sites of the mixed metal oxide-based MoCoOx@C-2 catalyst for the selective hydrodeoxygenation of vanillin to MMP, which is important for the academic and industrial catalysis community.