Outcomes and adverse events for spinal synovial cysts surgical treatment: a systematic review and meta-analysis.

BACKGROUND: Spinal synovial cysts (SSCs) are a rare cause of nerve root and spinal cord compression. Surgical excision of SSCs remains the mainstay of treatment in the presence of unremitting symptoms or neurological deficits, but the choice of the surgical approach remains controversial. The goal of this study was to compare clinical outcomes and adverse events associated with traditional approaches (interlaminar or laminectomy/hemilaminectomy) and minimally invasive approaches (microsurgical tubular approaches or endoscopic approaches) for SSCs. METHODS: Studies reporting surgical management of SSCs were searched in three online databases (PubMed, the Cochrane Library, and Web of Science). This meta-analysis was reported following the PRISMA Statement. It was registered at the International Prospective Register of Systematic Reviews (CRD42021288992). The Cochrane Collaboration's Risk of Bias in Nonrandomised Studies-of Interventions (ROBINS-I) was used to evaluate bias. Extracted research data were statistically analyzed using Stata 16 and SPSS statistics 25. RESULTS: A total of 22 related relevant studies were included. Meta-analysis revealed no statistically significant difference in dural tear, residual cyst, recurrence, reoperation, and operation time between minimally invasive approaches and traditional approaches (p > 0.05), but minimally invasive approaches had a good functional improvement (p = 0.004). Postoperative length of hospital stays and intraoperative bleeding in traditional approaches were also higher than in minimally invasive approaches (p < 0.05). CONCLUSION: Based on the available evidence, minimally invasive approaches may be better than traditional approaches in the treatment of SSCs. Minimally invasive approaches had the advantages of improving clinical satisfaction, with a similar complication rate to traditional approaches. Moreover, endoscopic and microsurgical tubular approaches had similar outcomes.

Engineering ZrO2-Ru interface to boost Fischer-Tropsch synthesis to olefins.

Understanding the structures and reaction mechanisms of interfacial active sites in the Fisher-Tropsch synthesis reaction is highly desirable but challenging. Herein, we show that the ZrO2-Ru interface could be engineered by loading the ZrO2 promoter onto silica-supported Ru nanoparticles (ZrRu/SiO2), achieving 7.6 times higher intrinsic activity and ~45% reduction in the apparent activation energy compared with the unpromoted Ru/SiO2 catalyst. Various characterizations and theoretical calculations reveal that the highly dispersed ZrO2 promoter strongly binds the Ru nanoparticles to form the Zr-O-Ru interfacial structure, which strengthens the hydrogen spillover effect and serves as a reservoir for active H species by forming Zr-OH* species. In particular, the formation of the Zr-O-Ru interface and presence of the hydroxyl species alter the H-assisted CO dissociation route from the formyl (HCO*) pathway to the hydroxy-methylidyne (COH*) pathway, significantly lowering the energy barrier of rate-limiting CO dissociation step and greatly increasing the reactivity. This investigation deepens our understanding of the metal-promoter interaction, and provides an effective strategy to design efficient industrial Fisher-Tropsch synthesis catalysts.

Microwave-Assisted Pyrolysis-A New Way for the Sustainable Recycling and Upgrading of Plastic and Biomass: A Review.

The efficient utilization of organic solid waste resources can help reducing the consumption of conventional fossil fuels, mitigating environmental pollution, and achieving green sustainable development. Due to its dual nature of being both a resource and a source of pollution, it is crucial to implement suitable recycling technologies throughout the recycling and upgrading processes for plastics and biomass, which are organic solid wastes with complex mixture of components. The conventional pyrolysis and hydropyrolysis were summarized for recycling plastics and biomass into high-value fuels, chemicals, and materials. To enhance reaction efficiency and improve product selectivity, microwave-assisted pyrolysis was introduced to the upgrading of plastics and biomass through efficient energy supply especially with the aid of catalysts and microwave absorbers. This review provides a detail summary of microwave-assisted pyrolysis for plastics and biomass from the technical, applied, and mechanistic perspectives. Based on the recent technological advances, the future directions for the development of microwave-assisted pyrolysis technologies are predicted.

Molten-Salt Electrochemical-Assisted Synthesis of the CeO2-OV@GC Composite-Supported Pt Clusters with a Pt-O-Ce Structure for the Oxygen Reduction Reaction.

Highly active and robust Pt-based electrocatalysts for an oxygen reduction reaction (ORR) are of crucial significance for the development of proton exchange membrane fuel cells (PEMFCs). Herein, the high-loading and well-dispersive Pt clusters on graphitic carbon-supported CeO2 with abundant oxygen vacancies (PtAC/CeO2-OV@GC) were successfully fabricated by a molten-salt electrochemical-assisted method. The bonding of Pt with the highly electronegative O induces charge redistribution through the Pt-O-Ce structure, thus reducing the adsorption energies of oxygen-containing species. Such a PtAC/CeO2-OV@GC electrocatalyst exhibits a greatly enhanced ORR performance with a mass activity of 0.41 ± 0.02 A·mg-1Pt at 0.9 V versus a reversible hydrogen electrode, which is 2.7 times the value of a commercial Pt/C catalyst and shows negligible activity decay after 20000 cycles of accelerated degradation tests. It is anticipated that this work will provide enlightening guidance on the controllable synthesis and rational design of high-performance Pt-based electrocatalysts for PEMFCs.

Reactivity of surface oxygen vacancy sites and frustrated Lewis acid-base pairs of In2O3 catalysts in CO2 hydrogenation.

The effects of oxygen vacancy (VO) formation energy and surface frustrated Lewis acid-base pairs (SFLPs) on the CO2 hydrogenation activity of In2O3 catalysts were studied using density functional theory calculations. The VO formation energy of 2.8-3.3 eV was found to favor HCOO formation, whereas the presence of SFLPs is conducive to CO formation.

Computational screening of single-atom doped In2O3 catalysts for the reverse water gas shift reaction.

The reverse water gas shift (RWGS) reaction is an important method for converting carbon dioxide (CO2) into valuable chemicals and fuels by hydrogenation. In this paper, the catalytic activity of single-atom metal-doped (M = Pt, Ir, Pd, Rh, Cu, Ni) indium oxide (c-In2O3) catalysts in the cubic phase for the RWGS reaction was investigated using density functional theory (DFT) calculations. This was achieved by identifying metal sites, screening oxygen vacancies, followed by further calculating the energy barriers for the direct and indirect dissociation pathways of the RWGS reaction. Our results show that the single-atom dopant in the indium oxide lattice promotes the creation of oxygen vacancies on the In2O3 surface, thereby facilitating the adsorption and activation of CO2 by the oxide surface and initiating the subsequent RWGS reaction. Furthermore, we find that the oxygen vacancy (OV) formation energy on the surface of the single-atom metal doped c-In2O3(111) surface can be used as a descriptor for CO2 adsorption, and the higher the OV formation energy, the more stable the CO2 adsorption structure is. The Cu/In2O3 structure has relatively high energy barriers for both direct (1.92 eV) and indirect dissociation (2.09 eV) in the RWGS reaction, indicating its low RWGS reactivity. In contrast, the Ir/In2O3 and Rh/In2O3 structures are more conducive to the direct dissociation of CO2 into CO, which may serve as more efficient RWGS catalysts. Furthermore, microkinetic simulations show that single atom metal doping to In2O3 enhances CO2 conversion, especially under high reaction temperatures, where the formation of oxygen vacancies is the limiting factor for CO2 reactivity on the M/In2O3 (M = Cu, Ir, Rh) models. Among these three single-atom catalysts, the Ir/In2O3 model was predicted to have the best CO2 reactivity at reaction temperatures above 573 K.

Efficacy of minimally invasive tubular approaches for management of the lumbar spinal synovial cysts: a meta-analysis.

The treatment of lumbar spinal synovial cysts (LSCs) which are relatively rare but can cause neurogenic dysfunction and intractable pain has been a controversial topic for many years. Surgical excision of LSCs is the standard treatment for patients in whom conservative treatment options fail. This meta-analysis was undertaken to compare clinical outcomes between minimally invasive approaches using tubular retractors (microscopic vs. endoscopic) and traditional percutaneous approaches for LSCs. Studies reporting surgical management of LSCs were searched in the Cochrane Library, PubMed and Web of Science database. This meta-analysis was reported following the PRISMA Statement, registered in Prospero (CRD42021288992). A total of 1833 patients were included from both the related relevant studies (41 studies, n = 1831) and the present series (n = 2). Meta-analysis of minimally invasive tubular approaches revealed no statistically significant difference in pain improvement, dural tear, residual cyst, recurrence and operation time between minimal groups with traditional groups (p > 0.05). Minimal groups had better Functional improvement of 100% (95% CI 1.00-1.00; p < 0.001, I2 = 75.3%) and less reoperation rates of 0% (95% CI - 0.00-0.00; p = 0.007, I2 = 47.1%). Postoperative length of hospital stay and intraoperative bleeding in minimal groups were also less than traditional groups (p < 0.05). Subgroup analysis revealed endoscopic groups had less operation time (p = 0.004), and there was no significant difference in the rest. For patients with LSCs but without obvious clinical and imaging evidence of vertebral instability, even when preoperative stable grade 1 spondylolisthesis is present, minimally invasive tubular approaches without fusion may provide the best outcome in surgical management.

Multiscale simulation of the effect of low-intensity pulsed ultrasound on the mechanical properties distribution of osteocytes.

Low-intensity pulsed ultrasound (LIPUS) is a potential effective means for the prevention and treatment of disuse osteoporosis. In this paper, the effect of LIPUS exposure on the mechanical properties distribution of the osteocyte system (osteocyte body contains nucleus, osteocyte process, and primary cilia) is simulated. The results demonstrate that the mechanical micro-environment of the osteocyte is significantly improved by ultrasound exposure, and the mean von Mises stress of the osteocyte system increases linearly with the excitation sound pressure amplitude. The mechanical effect of LIPUS on osteocytes is enhanced by the stress amplification mechanism of the primary cilia and osteocyte processes.

Interferon-γ inducible protein 30 promotes the epithelial-mesenchymal transition-like phenotype and chemoresistance by activating EGFR/AKT/GSK3ß/ß-catenin pathway in glioma.

AIMS: Previous studies have indicated that IFI30 plays a protective role in human cancers. However, its potential roles in regulating glioma development are not fully understood. METHODS: Public datasets, immunohistochemistry, and western blotting (WB) were used to evaluate the expression of IFI30 in glioma. The potential functions and mechanisms of IFI30 were examined by public dataset analysis; quantitative real-time PCR; WB; limiting dilution analysis; xenograft tumor assays; CCK-8, colony formation, wound healing, and transwell assays; and immunofluorescence microscopy and flow cytometry. RESULTS: IFI30 was significantly upregulated in glioma tissues and cell lines compared with corresponding controls, and the expression level of IFI30 was positively associated with tumor grade. Functionally, both in vivo and in vitro evidence showed that IFI30 regulated the migration and invasion of glioma cells. Mechanistically, we found that IFI30 dramatically promoted the epithelial-mesenchymal transition (EMT)-like process by activating the EGFR/AKT/GSK3ß/ß-catenin pathway. In addition, IFI30 regulated the chemoresistance of glioma cells to temozolomide directly via the expression of the transcription factor Slug, a key regulator of the EMT-like process. CONCLUSION: The present study suggests that IFI30 is a regulator of the EMT-like phenotype and acts not only as a prognostic marker but also as a potential therapeutic target for temozolomide-resistant glioma.

Molten-Salt Electrochemical Deoxidation Synthesis of Platinum-Neodymium Nanoalloy Catalysts for Oxygen Reduction Reaction.

Platinum-rare earth metal (Pt-RE) nanoalloys are regarded as a potential high performance oxygen reduction reaction (ORR) catalyst. However, wet chemical synthesis of the nanoalloys is a crucial challenge because of the extremely high oxygen affinity of RE elements and the significantly different standard reduction potentials between Pt and RE. Here, this paper presents a molten-salt electrochemical synthetic strategy for the compositional-controlled preparation of platinum-neodymium (Pt-Nd) nanoalloy catalysts. Carbon-supported platinum-neodymium (Ptx Nd/C) nanoalloys, with distinct compositions of Pt5 Nd and Pt2 Nd, are obtained through molten-salt electrochemical deoxidation of platinum and neodymium oxide (Pt-Nd2 O3 ) precursors supported on carbon. The Ptx Nd/C nanoalloys, especially the Pt5 Nd/C exhibit a mass activity of 0.40 A mg-1 Pt and a specific activity of 1.41 mA cm-2 Pt at 0.9 V versus RHE, which are 3.1 and 7.1 times higher, respectively, than that of commercial Pt/C catalyst. More significantly, the Pt5 Nd/C catalyst is remarkably stable after undergoing 20 000 accelerated durability cycles. Furthermore, the density-functional-theory (DFT) calculations confirm that the ORR catalytic performance of Ptx Nd/C nanoalloys is enhanced by compressive strain effect of Pt overlayer, causing a suitable weakened binding energies of O* Δ E O ∗ $\Delta {E}_{{{\rm{O}}}^*}$ and Δ E OH ∗ $\Delta {E}_{{\rm{OH}}^*}$ .

N6-methyladenosine reader IGF2BP3 as a prognostic Biomarker contribute to malignant progression of glioma.

Background: Glioblastoma (GBM) is a highly aggressive cancer having a dismal prognosis. N6-methyladenosine (m6A) is closely related to GBM progression. The significance of m6A modifications depends on the m6A readers, whose functions in glioma progression are largely unknown. This study sought to investigate the expression of the m6A related gene in glioma and its effect on the malignant progression of glioma. Methods: The expression differences between low-grade gliomas (LGGs) and high-grade gliomas (HGGs), and among 19 m6A-related genes were analyzed by The Cancer Genome Atlas (TCGA). Survival probability was analyzed in terms of the high or low expression of insulin growth factor-2 binding protein 3 (IGF2BP3) in the TCGA data set. The clinicopathological data of 40 patients with glioma were analyzed retrospectively, and the expression of IGF2BP3 in the tumor tissues was analyzed by immunohistochemistry (IHC). Lentiviral vectors harboring short-hairpin RNA (shRNA) were used to knock down IGF2BP3 in the glioma cell lines U87 and U251, and the results were verified by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blot. The effects of IGF2BP3 on the proliferation, invasion, and tumorigenicity of the glioma cells were verified by Cell Counting Kit-8 (CCK-8), transwell invasion, and subcutaneous tumorigenesis experiments in nude mice. The cell cycle phases were measured by flow cytometry. Results: The sequencing of TCGA data identified IGF2BP3 as the most significantly altered m6A-related gene. Patients with high IGF2BP3 expression had a significantly reduced survival probability (P<0.001) compared to those with low IGF2BP3 expression. IGF2BP3 was more upregulated in the HGGs than the LGGs. The downregulation of IGF2BP3 inhibited the proliferation, migration, and invasiveness of the glioma cells, and xenograft tumor growth in the mice. According to TCGA data, IGF2BP3 was closely related to cell cycle regulators, such as cyclin-dependent kinase 1 (CDK1) and cell-division cycle protein 20 homologue (CDC20). Further, the knockdown of IGF2BP3 affected the expression of CDK1 and the cell cycle process. Conclusions: IGF2BP3 expression in glioma is positively correlated with tumor grade and enhanced glioma cell proliferation, invasion, and tumorigenicity. IGF2BP3 knockdown decreased the expression of CDK1 and the cell cycle process. The current study showed that IGF2BP3 may serve as a biomarker of prognosis and a therapeutic target in glioma.

DFT-based microkinetic studies on methanol synthesis from CO2 hydrogenation over In2O3 and Zr-In2O3 catalysts.

Density functional theory (DFT) calculations and microkinetic simulations were performed to study the structure-performance relationship of In2O3 and Zr-doped In2O3 catalysts for methanol synthesis, focusing on the In2O3(110) and Zr-doped In2O3(110) surfaces. These surfaces are expected to follow the oxygen vacancy-based mechanism via the HCOO route for CO2 hydronation to methanol. Our DFT calcualtions show that the Zr-In2O3(110) surface is more favorable for CO2 adsorption than the In2O3(110) surface, and although the energy barriers are not lowered, most intermediates in the HCOO route are stablized with the introduction of the Zr dopant. Microkinetic simulations suggest that the CH3OH formation rate is improved by ∼10 times and CH3OH selectivity increased significantly from 10% on In2O3(110) to 100% on the Zr1-In2O3(110) catalyst model at 550 K. We find that the higher CH3OH formation rate and CH3OH selectivity on the Zr1-In2O3(110) surface than those on the In2O3(110) surface can be attributed to the slightly increased OV formation energy and the stablization of the reaction intermediates, whereas the much lower CH3OH formation rate on the Zr3-In2O3(110) surface is due to the much higher OV formation energy and the over binding of the H2O at the OV site.

Highly Selective Photoelectroreduction of Carbon Dioxide to Ethanol over Graphene/Silicon Carbide Composites.

Using sunlight to produce valuable chemicals and fuels from carbon dioxide (CO2 ), i.e., artificial photosynthesis (AP) is a promising strategy to achieve solar energy storage and a negative carbon cycle. However, selective synthesis of C2 compounds with a high CO2 conversion rate remains challenging for current AP technologies. We performed CO2 photoelectroreduction over a graphene/silicon carbide (SiC) catalyst under simulated solar irradiation with ethanol (C2 H5 OH) selectivity of>99 % and a CO2 conversion rate of up to 17.1 mmol gcat -1 h-1 with sustained performance. Experimental and theoretical investigations indicated an optimal interfacial layer to facilitate the transfer of photogenerated electrons from the SiC substrate to the few-layer graphene overlayer, which also favored an efficient CO2 to C2 H5 OH conversion pathway.

LncRNA SPRY4-IT1 facilitates cell proliferation and angiogenesis of glioma via the miR-101-3p/EZH2/VEGFA signaling axis.

BACKGROUND: SPRY4-IT1 (SPRY4 intronic transcript 1) is a long non-coding RNA (lncRNA) that has been identified as a novel oncogene in various cancers, including glioma. However, its function and underlying mechanism in glioma remain largely unclear. Here, we investigated the role of SPRY4-IT1 in the development of glioma and its underlying mechanism. METHODS: Bioinformatics analysis and RT-qPCR assay were used to examine the expression of SPRY4-IT1 in glioma tissues. The CCK-8, EdU, and Xenograft tumor assays wereperformed to assess the proliferation effect of glioma cells. The tube forming assay and Chick Embryo Chorioallantoic Membrane (CAM) assay were conducted to detect the angiogenesis effect of HUVECs. RNA-sequencing, western blotting, RT-qPCR, ELISA, and IHC assays were employed to verify the regulatory mechanism of the SPRY4-IT1/ miR-101-3p/EZH2/VEGFA axis. RESULTS: Analysis of the TCGA dataset and data from our own cohort demonstrated that SPRY4-IT1 was overexpressed in patients with glioma, and high SPRY4-IT1 expression correlated with poor prognosis. In vitro and in vivo experiments showed that SPRY4-IT1 promoted the proliferation of glioma cells. RNA sequencing and Gene Ontology (GO) enrichment analysis indicated significant enrichment of angiogenesis. HUVEC tube forming assay and CAM assay confirmed that SPRY4-IT1 could induce angiogenesis of glioma cells in vitro and in vivo. Mechanistically, SPRY4-IT1 upregulated EZH2 expression by sponging miR-101-3p to induce VEGFA expression in glioma cells. Moreover, SPRY4-IT1 activated the VEGFR2/AKT/ERK1/2 pathway in HUVECs mediated by glioma cells. Rescue experiments further confirmed that SPRY4-IT1 promoted glioma cell proliferation and angiogenesis via the miR-101-3p/EZH2/VEGFA signaling axis. CONCLUSIONS: Our findings provide compelling evidence showing that SPRY4-IT1 upregulated EZH2 to induce VEGFA by sponging miR-101-3p, thereby achieving cell proliferation and angiogenesis in glioma. Therefore, targeting SPRY4-IT1/miR-101-3p/EZH2/VEGFA axis may improve the outcomes of patients with glioma.

Water interaction with B-site (B = Al, Zr, Nb, and W) doped SrFeO3-δ-based perovskite surfaces for thermochemical water splitting applications.

Density functional theory (DFT) calculations were performed to study the interaction of water with the SrO and FeO2 terminations of the SrFeO3-δ (001) surface, where the effects of the metal dopants (Al, Zr, Nb, and W), surface oxygen vacancies, and oxygen ion migration were investigated. Our calculations showed that the metal dopants benefited the molecular and dissociative adsorptions of H2O on both the perfect and oxygen-vacancy-containing surfaces. The surface oxygen vacancies were predicted to promote the dissociative adsorption of H2O and the formation of H2. For all structures studied, H2 release was found to be always an overall endothermic process, except for the W-doped structure which will become exothermic at high temperature. On the oxygen-vacancy-containing surface, H2 generation was predicted to be easier at the SrO termination than the FeO2 termination. Furthermore, we also investigated the oxygen ion migration mechanism on all surface structures, predicted the behaviour of oxygen migration and the effect of oxygen vacancy defects. Our results showed that Al doping facilitated not only the formation of surface oxygen vacancies, but also oxygen migration from the surface to the subsurface, in contrast to the Zr, Nb and W-doped structures. This study provided significant insights into the interaction of water with the surfaces of doped SrFeO3-δ perovskite materials for thermochemical water splitting applications.

Direct production of olefins from syngas with ultrahigh carbon efficiency.

Syngas conversion serves as a competitive strategy to produce olefins chemicals from nonpetroleum resources. However, the goal to achieve desirable olefins selectivity with limited undesired C1 by-products remains a grand challenge. Herein, we present a non-classical Fischer-Tropsch to olefins process featuring high carbon efficiency that realizes 80.1% olefins selectivity with ultralow total selectivity of CH4 and CO2 (<5%) at CO conversion of 45.8%. This is enabled by sodium-promoted metallic ruthenium (Ru) nanoparticles with negligible water-gas-shift reactivity. Change in the local electronic structure and the decreased reactivity of chemisorbed H species on Ru surfaces tailor the reaction pathway to favor olefins production. No obvious deactivation is observed within 550 hours and the pellet catalyst also exhibits excellent catalytic performance in a pilot-scale reactor, suggesting promising practical applications.

GBP3 promotes glioblastoma resistance to temozolomide by enhancing DNA damage repair.

Glioblastoma is the most common malignant brain cancer with dismal survival and prognosis. Temozolomide (TMZ) is a first-line chemotherapeutic agent for glioblastoma, but the emergence of drug resistance limits its anti-tumor activity. We previously discovered that the interferon inducible guanylate binding protein 3 (GBP3) is highly elevated and promotes tumorigenicity of glioblastoma. Here, we show that TMZ treatment significantly upregulates the expression of GBP3 and stimulator of interferon genes (STING), both of which increase TMZ-induced DNA damage repair and reduce cell apoptosis of glioblastoma cells. Mechanistically, relying on its N-terminal GTPase domain, GBP3 physically interacts with STING to stabilize STING protein levels, which in turn induces expression of p62 (Sequestosome 1), nuclear factor erythroid 2 like 2 (NFE2L2, NRF2), and O6-methlyguanine-DNA-methyltransferase (MGMT), leading to the resistance to TMZ treatment. Reducing GBP3 levels by RNA interference in glioblastoma cells markedly increases the sensitivity to TMZ treatment in vitro and in murine glioblastoma models. Clinically, GBP3 expression is high and positively correlated with STING, NRF2, p62, and MGMT expression in human glioblastoma tumors, and is associated with poor outcomes. These findings provide novel insight into TMZ resistance and suggest that GBP3 may represent a novel potential target for the treatment of glioblastoma.

Experimental and computational approaches to study the chlorination mechanism of pentlandite with ammonium chloride.

Pentlandite (Fe4.5Ni4.5S8) is the primary source for the metallurgical production of nickel worldwide, however it usually coexists with copper sulfide in nature. To develop an efficient and green process for the separation and extraction of valuable metals from the nickel sulfide concentrate, herein we conducted experimental studies and density functional theory (DFT) calculations to elucidate the chlorination mechanism of pentlandite using ammonium chloride (NH4Cl). First, low-temperature chlorination roasting experiments with NH4Cl were performed in which pentlandite was successfully converted into the corresponding metal chlorides (FeCl2 and NiCl2). Then, the chlorination product was analyzed via energy dispersive spectrometry to reveal the elemental distribution at the cross-section. Results reveal that Fe atoms in pentlandite underwent preferential chlorination to form a chloride layer, whereas Ni atoms remained at the center of the grain. Furthermore, density functional theory calculations were performed to investigate the chlorination mechanism of pentlandite by exploring two possible pathways, involving the adsorption of oxygen (O2), ammonium chloride (NH4Cl) and chlorine (Cl2) on both the (001) and (010) surfaces of pentlandite. Considering that the chlorination of pentlandite was achieved in air atmosphere, we first consider the direct chlorination of pentlandite by NH4Cl in the presence of oxygen. Dissociative oxygen adsorption was found to promote the chlorination process by providing oxygen sites for the dissociation of HCl, which is decomposed from NH4Cl, eventually leading to the formation of H2O and FeCl2 species. Alternatively, the reaction between pentlandite and Cl2 was proved to be feasible thermodynamically.

Revealing the different performance of Li4SiO4 and Ca2SiO4 for CO2 adsorption by density functional theory.

To reveal the difference between Li4SiO4 and Ca2SiO4 in CO2 adsorption performance, the CO2 adsorption on Li4SiO4 (010) and Ca2SiO4 (100) surfaces was investigated using density functional theory (DFT) calculations. The results indicate that the bent configuration of the adsorbed CO2 molecule parallel to the surface is the most thermodynamically favorable for both Li4SiO4 and Ca2SiO4 surfaces. The Li4SiO4 (010) surface has greater CO2 adsorption energy (E ads = -2.97 eV) than the Ca2SiO4 (100) surface (E ads = -0.31 eV). A stronger covalent bond between the C atom of adsorbed CO2 and an OS atom on the Li4SiO4 (010) surface is formed, accompanied by more charge transfer from the surface to CO2. Moreover, the Mulliken charge of OS atoms on the Li4SiO4 (010) surface is more negative, and its p-band center is closer to the E f, indicating OS atoms on Li4SiO4 (010) are more active and prone to suffering electrophilic attack compared with the Ca2SiO4 (100) surface.

Tandem Catalysis for Selective Oxidation of Methane to Oxygenates Using Oxygen over PdCu/Zeolite.

Selective oxidation of methane to oxygenates with O2 under mild conditions remains a great challenge. Here we report a ZSM-5 (Z-5) supported PdCu bimetallic catalyst (PdCu/Z-5) for methane conversion to oxygenates by reacting with O2 in the presence of H2 at low temperature (120 °C). Benefiting from the co-existence of PdO nanoparticles and Cu single atoms via tandem catalysis, the PdCu/Z-5 catalyst exhibited a high oxygenates yield of 1178 mmol g-1 Pd h-1 (mmol of oxygenates per gram Pd per hour) and at the same time high oxygenates selectivity of up to 95 %. Control experiments and mechanistic studies revealed that PdO nanoparticles promoted the in situ generation of H2 O2 from O2 and H2 , while Cu single atoms not only accelerated the activation of H2 O2 for the generation of abundant hydroxyl radicals (⋅OH) from H2 O2 decomposition, but also enabled the homolytic cleavage of CH4 by ⋅OH to methyl radicals (⋅CH3 ). Subsequently, the ⋅OH reacted quickly with the ⋅CH3 to form CH3 OH with high selectivity.