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The concept of green carbon science is to promote the goal of achieving carbon neutrality, the importance and urgency of which have been well‐recognized and received worldwide attention. Carbon neutrality has become the focus of research work in many fields, and correspondingly, a growing number of papers and publications have been published over the last few years. However, since carbon neutralization is a real problem that urgently requires technical solutions, the transition from fundamental research to practical applications must be accelerated. A number of research teams are bold in putting things into practice and blazing new trails. This Review summarizes the recent technological developments within the framework of green carbon science, focusing on conducted pilot tests, industrial demonstrations, and commercial applications beyond the laboratory stage. [ABSTRACT FROM AUTHOR]

The concept of green carbon science is to promote the goal of achieving carbon neutrality, the importance and urgency of which have been well‐recognized and received worldwide attention. Carbon neutrality has become the focus of research work in many fields, and correspondingly, a growing number of papers and publications have been published over the last few years. However, since carbon neutralization is a real problem that urgently requires technical solutions, the transition from fundamental research to practical applications must be accelerated. A number of research teams are bold in putting things into practice and blazing new trails. This Review summarizes the recent technological developments within the framework of green carbon science, focusing on conducted pilot tests, industrial demonstrations, and commercial applications beyond the laboratory stage. [ABSTRACT FROM AUTHOR]

Inspired by the nature fractal structure, a novel honeycomb fractal micro-reactor was designed and applied to intensify both heat and mass transfer in the exothermic conversion of syngas to olefins. The results show that the honeycomb fractal micro-reactor provides more even distribution of temperature profiles, a narrower reactant residence time distribution, and relative smaller pressure drop per unit length, compared with parallel straight microchannel reactor and mini-fixed bed reactor under the same reaction conditions. Owning to the reinforcement of flow separation and convergence in the honeycomb structure, the contact between reactants and catalyst particles were enhanced, leading to a better heat and mass transfer. Under the current range of temperature, pressure and standard GHSV, the honeycomb fractal micro-reactor leads to supreme CO conversion and lower olefins yield. [ABSTRACT FROM AUTHOR]

The synthesis of methanethiol from CS2 catalyzed by Ni-, Co-, or K-modified MoS2/SiO2 through the sequence CS2→CH3SH→CH3SCH3 (DMS) has been studied. CS2 is readily hydrogenated to CH3SH, whereas CH3SH and DMS decompose to CH4 at high CS2 conversions and temperatures. Thus, very high yields of CH3SH can be obtained on all the catalysts. The addition of Co or Ni accelerates all reaction steps to allow the formation of CH3SH under relatively mild conditions. On the contrary, K suppresses the formation of byproducts but also lowers the activity. The surface reaction proceeds through a series of hydrogen-addition steps, the rate-controlling step of which is the addition of the first H atom. H2 adsorbs dissociatively, whereas CS2 adsorbs strongly in a single active site prior to hydrogenation. The addition of Ni has a stronger enhancing effect on hydrogenation and accelerates the CS bond cleavage to a smaller extent than Co. Therefore, Ni leads to optimum CH3SH yields and holds the best promise as promoter for the MoS2 phase in the synthesis of methanethiol from CS2. [ABSTRACT FROM AUTHOR]

As a primary constituent of natural gas and shale gas, direct conversion of methane has attracted significant attention due to its potential to reduce energy consumption and CO2 emissions. Compared with thermal catalysis, photocatalysis has the capacity to transcend thermodynamic constraint and enable the conversion of sustainable solar energy into chemical energy under mild reaction condition, which contributes to optimize the utilization of methane. In this review, we undertake a comparative analysis of various strategies for photocatalytic methane conversion to syngas and chemicals, including photocatalytic reforming of methane, photocatalytic partial oxidation of methane and photocatalytic coupling of methane. The distinct reaction systems with corresponding catalysts and underlying mechanisms are expounded in detail to foster a profound comprehension of solar‐driven methane conversion. Finally, the challenges and prospectives in photocatalytic methane conversion are discussed. [ABSTRACT FROM AUTHOR]

Strong metal‐support interactions (SMSI) featuring the formation of encapsulation overlayer around metal nanoparticles has drawn much attention in heterogeneous catalysis. Recent years, various novel SMSI phenomena have been observed and the nature of SMSI also has been revealed with the improvement of characterization techniques. Understanding the SMSI effect could deepen the insight into the structure‐activity relationship of metal‐supported catalysts, and rationally guide the design of special metal‐interface sites to manipulate catalytic behavior in chemical reaction. In this review, the research progress of SMSI and its application in heterogeneous COx hydrogenation are briefly surveyed, with emphasis on the advanced characterization, manipulation strategy and specific role of SMSI in Fischer‐Tropsch synthesis process, CO2 methanation and Reverse Water Gas Shift reaction. The current challenges and perspectives for the development of SMSI are also discussed. [ABSTRACT FROM AUTHOR]

Syngas conversion is a useful technology for converting nonpetroleum carbon resources into chemicals such as olefins. Iron- and cobalt-based catalysts, as two major categories, have been extensively studied in Fischer–Tropsch synthesis to olefins (FTO) reactions. Although both iron and cobalt catalysts have shown distinct merits and shortcomings, they are also complementary in their properties and catalytic performances when combined with each other. Herein, Na-modified CoFe bimetallic catalysts were fabricated using a co-precipitation method. It was found that there was a synergistic effect between Co and Fe that promoted a CO dissociation rate and carburization, and an appropriate Co/Fe ratio was conducive to improvements in their catalytic performances. The desired olefins selectivity reached 66.1 C% at a CO conversion of 37.5% for a Co2Fe1 catalyst, while the methane selectivity was only 4.3 C%. In addition, no obvious deactivation was found after nearly 160 h, indicating their potential industrial application. [ABSTRACT FROM AUTHOR]

We develop an electric internal heating method based on a Ni-foam structured catalyst for CO2 methanation, in which the Joule heat generated by electric current passing through the catalyst drives the reaction. Compared with the conventional external heating method, EIH significantly enhances the catalytic activity and anti-poisoning ability of the catalyst. [ABSTRACT FROM AUTHOR]

MolybdENum carries the load The cover picture shows the reaction of CS2 and H2 over supported MoS2 ‐ type catalysts as a novel route for the synthesis of methanethiol, an important raw material in chemical industry. In their Full Paper on page   3249   ff., J.   A. Lercher and co ‐ workers describe the mechanism and kinetics of the reaction emphasizing the effect of Ni, Co, or K on the rates of hydrogENation and CS bond cleavage on MoS2. Thus, while aiming for the production of methanethiol with high rates and selectivity, the study also contributes to the understanding of the promotion of MoS2. [ABSTRACT FROM AUTHOR]

Photocatalytic methane oxidation to oxygenates with promising performance remains as a grand challenge due to the low productivity and severe overoxidation. Herein, SrWO4/TiO2 heterojunction was developed for photocatalytic methane oxidation with O2 to liquid oxygenates (Please replace "oxygenates" with "oxygenated")products under mild reaction conditions. The optimized SrWO4/TiO2 catalyst exhibited high productivity of 13365 μmol/g with high selectivity of 98.7 % for oxygenates. Benefited from the intimate heterojunction interface of SrWO4/TiO2, the constructed I‐type heterostructure improved the separation and transfer of photogenerated carriers, and a high‐speed transfer channel for photogenerated carriers was fabricated. Simultaneously, the special band structure can increase the amount of photogenerated electrons and holes on the TiO2 surface, which promoted the formation of reactive oxygen species to enhance liquid oxygenates productivity. [ABSTRACT FROM AUTHOR]

As a clean fossil energy and chemical feedstock, development of breakthrough strategies for direct conversion of methane (CH4) into various chemicals under mild reaction conditions is highly desired. Herein, Rh/ZSM‐5 catalyst was reported to convert CH4 to oxygenates with molecular oxygen (O2) in the presence of CO at low temperature with promising catalytic performance. The oxygenates productivity reached as high as 5638.0 μmol gcat.−1 h−1. Structure characterization confirmed the existence of highly dispersed Rh2O3 nanoparticles with an average diameter of 2.4 nm in the Rh/ZSM‐5 catalyst. Based on control experiments and mechanism study, it was suggested that CO plays a pivotal role over the Rh/ZSM‐5 catalyst to boost direct oxidation of methane. CO participates in water‐gas‐shift reaction to produce in‐situ H species, which enables to form *OH, *OOH and H2O2 active species by reacting with O2. The as‐obtained *OH, *OOH and H2O2 species will thus render high activity for methane oxidation. [ABSTRACT FROM AUTHOR]

Selective oxidation of methane to oxygenates using low‐cost and environment‐friendly molecular oxygen (O2) under mild reaction conditions is a promising strategy but still remains grand challenge. It is of great importance to accelerate the activation of O2 to generate highly active oxygen species, such as hydroxyl peroxide and hydroxyl species to improve catalytic performance for selective oxidation of methane. Selective oxidation of methane using O2 by coupling with in situ generation of hydrogen peroxide via tandem catalysis ensures the easy formation of active oxygen species for methane activation, leading to high oxygenates productivity under mild conditions. In this concept, we summarized the recent progresses for selective oxidation of methane to oxygenates using O2 based on tandem catalysis by coupling with in situ generation of hydrogen peroxide. The remaining challenges and future perspectives for selective oxidation of methane to oxygenates via tandem catalysis were also proposed. [ABSTRACT FROM AUTHOR]

Syngas conversion provides an important platform for efficient utilization of various carbon-containing resources such as coal, natural gas, biomass, solid waste and even CO2. Various value-added fuels and chemicals including paraffins, olefins and alcohols can be directly obtained from syngas conversion via the Fischer–Tropsch Synthesis (FTS) route. However, the product selectivity control still remains a grand challenge for FTS due to the limitation of Anderson–Schulz–Flory (ASF) distribution. Our previous works showed that, under moderate reaction conditions, Co2C nanoprisms with exposed (101) and (020) facets can directly convert syngas to olefins with low methane and high olefin selectivity, breaking the limitation of ASF. The application of Co2C-based nanocatalysts unlocks the potential of the Fischer–Tropsch process for producing olefins. In this feature article, we summarized the recent advances in developing highly efficient Co2C-based nanocatalysts and reaction pathways for direct syngas conversion to olefins via the Fischer–Tropsch to olefin (FTO) reaction. We mainly focused on the following aspects: the formation mechanism of Co2C, nanoeffects of Co2C-based FTO catalysts, morphology control of Co2C nanostructures, and the effects of promoters, supports and reactors on the catalytic performance. From the viewpoint of carbon utilization efficiency, we presented the recent efforts in decreasing the CO2 selectivity for FTO reactions. In addition, the attempt to expand the target products to aromatics by coupling Co2C-based FTO catalysts and H-ZSM-5 zeolites was also made. In the end, future prospects for Co2C-based nanocatalysts for selective syngas conversion were proposed. [ABSTRACT FROM AUTHOR]

The structure-performance evolution of Co/N-AC catalyst during ethylene oligomerization was investigated in detail. It was found that the catalytic activity sharply decreased in the first 30 h with the ethylene conversion decreasing from 64 to 4%. Butene selectivity increased gradually in the first 10 h then remained about 74%, while the selectivity for hexene and octene exhibited an opposite trend. The ratio of α-olefin to isomers for butene increased greatly with time on stream and most of the generated butene was 1-butene. Based on the structure characterization at different reaction stages, CoOx was suggested to be major active phase and the coverage of long-chain hydrocarbons as well as the loss of surface CoOx active sites due to size growth of Co3O4 nanoparticles were the main reasons for catalytic deactivation. The structure-performance evolution of Co/N-AC catalyst during ethylene oligomerization was investigated and the coverage of long-chain hydrocarbons as well as the loss of surface CoOx active sites due to size growth of Co3O4 nanoparticles were the main reasons for catalytic deactivation [ABSTRACT FROM AUTHOR]

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−1Pd 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 H2O2 from O2 and H2, while Cu single atoms not only accelerated the activation of H2O2 for the generation of abundant hydroxyl radicals (⋅OH) from H2O2 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 CH3OH with high selectivity. [ABSTRACT FROM AUTHOR]

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−1Pd 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 H2O2 from O2 and H2, while Cu single atoms not only accelerated the activation of H2O2 for the generation of abundant hydroxyl radicals (⋅OH) from H2O2 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 CH3OH with high selectivity. [ABSTRACT FROM AUTHOR]

Direct conversion of methane to acetic acid with high activity and selectivity over non-noble metal-based catalysts under mild reaction conditions remains a grand challenge. Specifically, 1.2Ni-ZSM-5 with 88.9 % isolated Ni sites achieved a high acetic acid yield of 2920 μ mol/g cat. and a remarkable selectivity up to 82.3 % from methane oxidative carbonylation. Combined with high angle annular dark field scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy analyses, it was revealed that the isolated Ni species with Ni-O 6 moieties anchored in the micropores of ZSM-5 were suggested to be the active sites. The isotopic labeling experiments and monitoring of reaction intermediates demonstrated that CH 3 COOH was formed via the direct coupling of methyl radicals and carbon monoxide molecules. This work suggests that the well-designed Ni sites can promote the transformation of CH 4 to C 2+ oxygenates instead of traditional C 1 oxygenates as main products. [Display omitted] • Non-noble Ni-based catalyst can promote the oxidative carbonylation of CH 4 to C 2+ oxygenates. • 2920 μ mol/g cat. of oxygenated products can be acquired with 82.3 % of CH 3 COOH selectivity. • The catalytic performance of Ni-ZSM-5 is comparable to these noble metal-based catalysts. • Isolated Ni sites anchored on zeolites was identified as active center. • The CH 3 COOH was formed via the direct coupling of ·CH 3 radicals and CO. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new RuK/Al 2 O 3 heterogeneous hydroformylation catalyst was developed. • RuK possesses higher activity and propanal selectivity than Ru, Rh and Co. • The structure-performance of the RuK and Ru catalysts was investigated. • The synergistic effect of Ru and K facilitates the formation of aldehydes. • K promoted Ru catalysts reduced the hydrogenation of olefins. Hydroformylation is a prototypical C-C coupling reaction of olefins and syngas to produce valuable higher aldehydes. In this study, we investigated the promotional effect of potassium (K) on Ru-based heterogeneous ethylene hydroformylation. The propanal selectivity could reach up to 84.9% at an ethylene (C 2 H 4) conversion of 10.7 % with the addition of K as a promoter. Furthermore, the formation of ethane and the second hydrogenation of olefins were effectively suppressed. Structural characterization results suggested that K promoter could enhance the dispersion of Ru species and increase the electronic density of Ru active sites, thus improving CO adsorption and dissociation. The synergistic effect of Ru and K created a C*-rich and H*-lean local chemical environment, facilitating the formation of aldehydes while effectively reducing the hydrogenation of olefins. This work may provide new insights for development promising Ru-based heterogeneous catalysts for hydroformylation. [ABSTRACT FROM AUTHOR]

A Ru single-atom (Ru SA) catalyst supported on activated carbon was adopted to synthesize 3-pentanone with 83.3% selectivity via heterogeneous ethylene hydroformylation, while 52.1% ethane selectivity was obtained for Ru nanoparticles (Ru NPs). The atomically dispersed Ru species with oxidation state (Ruδ+) and Ru-C4O coordination structure were identified as the active sites for efficient C–C coupling to generate 3-pentanone, while metallic Ru nanoparticles exhibited high activity for ethylene hydrogenation to ethane. Density functional theory (DFT) calculation revealed that the energy barrier of the direct coupling of C2H5CO* with C2H5* to form 3-pentanone on Ru SA was much lower than that on Ru NPs. As a result, the formation of 3-pentanone over Ru SA was more favourable than propanal, which was admittedly generated via coupling of C2H5CO* and H*. This strategy may provide a potential green route for the one-pot synthesis of 3-pentanone with high atomic economy. [ABSTRACT FROM AUTHOR]

As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway. [ABSTRACT FROM AUTHOR]

A green route for one−pot synthesis of acetals by tandem hydroformylation−acetalization of olefins using supported Rh−based catalysts was developed. Experimental results demonstrated that suitable Rh loading (1 wt%) with appropriate reaction temperature (120 °C) and reaction time (8 h) were favorable for the formation of acetals, and a high acetals selectivity of 94.6% was achieved. More importantly, the selectivity to valuable linear products was enhanced in this tandem catalysis. Based on the catalytic mechanism study, highly dispersed RhOx nanoparticles and abundant acid sites on the supports were responsible for the hydroformylation and acetalization, respectively. One-pot synthesis of acetals directly from olefins with high selectivity was achieved over heterogeneous bifunctional catalysts via tandem hydroformylation-acetalization. [ABSTRACT FROM AUTHOR]

Selectivity control of nitrobenzene hydrogenation remains a great challenge, and it is desirable to develop a green and highly efficient catalytic route toward value-added metastable intermediate products. Herein, we reported that isolated Ru single atoms coordinated with oxygen atoms in CeO2 (Ru-SAs/CeO2) can achieve chemoselective hydrogenation of nitrobenzene to azoxybenzene with a selectivity of 88.2% in a continuous flow reactor using H2 without using any bases or expensive organic reducing agents, while 82.7% aniline selectivity was obtained by Ru nanoparticles. We demonstrated that the unique coordinated structure between Ru single atoms and O atoms preferentially controls the reaction route toward the coupling of nitrosobenzene and phenylhydroxylamine intermediates to form azoxybenzene while greatly suppressing over-hydrogenation. The present work provides an efficient strategy to regulate the reaction pathway of nitrobenzene hydrogenation with a green and industry-friendly process by designing highly dispersed Ru single atoms. [ABSTRACT FROM AUTHOR]

Cu single atoms embedded in the C3N4 (Cu-SAs/C3N4) matrix exhibited high activity with 95% oxygenate selectivity for the direct conversion of methane at ambient temperature. The presence of abundant anchoring sites in C3N4 led to highly dispersed Cu–N4 moieties, which were suggested to be the underlying active sites for methane conversion. [ABSTRACT FROM AUTHOR]

Gamma‐ray (γ‐ray) irradiation was introduced into zeolite synthesis. The crystallization process of zeolite NaA, NaY, Silicalite‐1, and ZSM‐5 were greatly accelerated. The crystallization time of NaA zeolite was significantly decreased to 18 h under γ‐ray irradiation at 20 °C, while more than 102 h was needed for the conventional process. Unexpectedly, more mesopores were created during this process, and thus the adsorption capacity of CO2 increased by 6‐fold compared to the NaA prepared without γ‐ray irradiation. Solid experimental evidence and density function theory (DFT) calculations demonstrated that hydroxyl free radicals (OH*) generated by γ‐rays accelerated the crystallization of zeolite NaA. Besides NaA, mesoporous ZSM‐5 with MFI topology was also successfully synthesized under γ‐ray irradiation, which possessed excellent catalytic performance for methanol conversion, suggesting the universality of this new synthetic strategy for various zeolites. [ABSTRACT FROM AUTHOR]

Gamma‐ray (γ‐ray) irradiation was introduced into zeolite synthesis. The crystallization process of zeolite NaA, NaY, Silicalite‐1, and ZSM‐5 were greatly accelerated. The crystallization time of NaA zeolite was significantly decreased to 18 h under γ‐ray irradiation at 20 °C, while more than 102 h was needed for the conventional process. Unexpectedly, more mesopores were created during this process, and thus the adsorption capacity of CO2 increased by 6‐fold compared to the NaA prepared without γ‐ray irradiation. Solid experimental evidence and density function theory (DFT) calculations demonstrated that hydroxyl free radicals (OH*) generated by γ‐rays accelerated the crystallization of zeolite NaA. Besides NaA, mesoporous ZSM‐5 with MFI topology was also successfully synthesized under γ‐ray irradiation, which possessed excellent catalytic performance for methanol conversion, suggesting the universality of this new synthetic strategy for various zeolites. [ABSTRACT FROM AUTHOR]

Cobalt carbide (Co2C) exhibits strong facet effect for Fischer‐Tropsch to olefins (FTO) reaction. Herein, we report that the facet proportion of Co2C nanostructures can be tuned effectively by incorporating and altering the Mn content in the CoMn composite oxide as catalyst precursor. With the addition of Mn promoter, the Co2C nanoprisms with exposed (020) and (101) facets are generated under reaction conditions. In addition, the facet proportion of Co2C(020) facet can be effectively improved by enhancing the Mn/Co ratio. With the increase of facet proportion of Co2C(020)/Co2C(101) ratio, the as‐obtained Co2C nanoprisms exhibit higher intrinsic activity and lower methane selectivity during the syngas conversion process. Kinetic experiments also demonstrate that the apparent activation energy (Ea) for CO conversion is significantly reduced as increasing the facet proportion of Co2C(020). This work provides a simple and feasible way to tune the exposed facet proportion for the rational design of Co2C nanocatalyst for FTO reaction. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch to olefins (FTO) with controllable iron carbide phase and high carbon utilization efficiency for Fe-based nanocatalyst attracts great interest but remains challenge. Herein, we report that the metastable Fe 7 C 3 phase can be effectively tailored by altering shell thickness of hydrophobic SiO 2 over a core-shell nanostructured FeZn@SiO 2 -c nanocatalyst. χ-Fe 5 C 2 was the dominated iron carbide phase for FeZnO x and FeZn@SiO 2 nanocatalysts, while numerous Fe 7 C 3 phases existed for hydrophobic FeZn@SiO 2 -c nanospheres. Compared with FeZnO x , the CO 2 selectivity of FeZn@ 4.1-SiO 2 -c decreased by > 70%, while 1.7-fold higher olefins selectivity was simultaneously obtained during syngas conversion process. The hydrophobic interface greatly suppressed the water-gas-shift reaction by promoting the quick diffusion of water, and the as-formed H 2 -lean and CO-rich local chemical environment benefits the formation of Fe 7 C 3 and olefins products. This work provides a promising strategy to design phase-stable Fe 7 C 3 with improvement of carbon efficiency for Fe-based nanocatalysts. [Display omitted] • Hydrophobic interfaces could regulate iron carbide phases. • Hydrophobic confined environment benefits the design of phase-stable Fe 7 C 3 carbide. • Fe 7 C 3 is a favorable active phase for Fischer-Tropsch to olefins (FTO). • Wettability environment affects WGS reaction activity and FTO performance. • Suppressed CO 2 selectivity, enhanced activity and olefins selectivity was obtained. [ABSTRACT FROM AUTHOR]

An atomically economical green protocol for the hydrofunctionalization of olefins to higher aliphatic alcohols with 100% anti-Markovnikov regioselectivity was developed via visible-light photocatalytic coupling. This method employs cheap, readily available and abundant methanol as both the C1 feedstock and the hydrogen source under visible light irradiation over CdS photocatalyst. A wide scope of olefin substrates could be hydrofunctionalized successfully to the corresponding higher alcohols with high selectivity. Besides alcohol, acetone and acetonitrile can also couple with olefins to generate the corresponding hydrofunctionalization products, suggesting promising potential industrial application. Hydrofunctionalization of olefins to value-added chemicals with high selectivity was achieved via visible-light photocatalytic cross-coupling. [ABSTRACT FROM AUTHOR]

Selective synthesis of higher oxygenates (linear α‐alcohols and α‐aldehydes, C2+ OH) from syngas is highly attractive but remains challenging owing to the low C2+ OH selectivity and low catalytic stability. Herein we introduce a multifunctional catalyst composed of CoMn and CuZnAlZr oxides that dramatically increased the oxygenates selectivity to 58.1 wt %, where more than 92.0 wt % of the produced oxygenates are C2+ OH. Notably, the total selectivity to value‐added chemicals including oxygenates and olefins reached 80.6 wt % at CO conversion of 29.0 % with high stability. The appropriate component proximity can effectively suppress the formation of the undesired C1 products, and the selectively propulsion of reaction network by synergetic effect of different components contributes to the enhanced selectivity to higher oxygenates. This work provides an alternative strategy for the rational design of new catalysts for direct conversion of syngas into higher oxygenates with co‐production of olefins. A stable multifunctional catalyst composed of CoMn oxides and CuZnAlZr oxides was developed for direct conversion of syngas to higher oxygenates and olefins with a total selectivity of 80.6 wt % at a CO conversion of 29.0 %. The interaction manner of the two components plays a crucial role in suppressing C1 products formation and enhancing the selectivity to higher oxygenates. [ABSTRACT FROM AUTHOR]

Selective synthesis of higher oxygenates (linear α‐alcohols and α‐aldehydes, C2+ OH) from syngas is highly attractive but remains challenging owing to the low C2+ OH selectivity and low catalytic stability. Herein we introduce a multifunctional catalyst composed of CoMn and CuZnAlZr oxides that dramatically increased the oxygenates selectivity to 58.1 wt %, where more than 92.0 wt % of the produced oxygenates are C2+ OH. Notably, the total selectivity to value‐added chemicals including oxygenates and olefins reached 80.6 wt % at CO conversion of 29.0 % with high stability. The appropriate component proximity can effectively suppress the formation of the undesired C1 products, and the selectively propulsion of reaction network by synergetic effect of different components contributes to the enhanced selectivity to higher oxygenates. This work provides an alternative strategy for the rational design of new catalysts for direct conversion of syngas into higher oxygenates with co‐production of olefins. [ABSTRACT FROM AUTHOR]

Graphical abstract Morphology control of Co 2 C nanostructures via reduction process was developed for direct production of lower olefins from syngas. The structure-performance of the as-obtained Co 2 C nanoprisms and nanospheres were investigated based on kinetic study and DFT calculations. Highlights • Morphology control of Co 2 C nanostructures via reduction process was developed. • Co 2 C nanoprisms or nanospheres can be obtained by controlling the reduction process. • The structure-performance of the as-obtained Co 2 C nanoprisms and nanospheres was investigated. • Co 2 C nanoprisms possessed higher activity and lower methane selectivity than Co 2 C nanospheres. • The product distribution of Co 2 C nanoprisms deviated from the ASF law. Abstract Fischer-Tropsch to olefins (FTO) is recognized as a surface-catalyzed structure-sensitive reaction, and the catalytic performance is strongly influenced by the morphology and exposed facets of the active phase. Here we report the effect of the reduction process on the morphology of the active phase and the catalytic performance for FTO over the CoMn catalyst. For the catalysts reduced by 10% CO-300 °C, 10% H 2 -300 °C and 10% H 2 -250 °C, Co 2 C nanoprisms were formed after reaching the steady state. However, for the catalysts reduced by CO-300 °C and 10% H 2 -400 °C, Co 2 C nanospheres were found instead. Both Co 2 C nanoprisms and nanospheres were present for the spent sample reduced by 10% H 2 -350 °C. Kinetic study found Co 2 C nanospheres to possess higher activation energy, and are more sensitive to hydrogen than Co 2 C nanoprisms. Density functional theory (DFT) calculations were also performed to clarify the structure-performance relationship of Co 2 C nanostructures for syngas conversion. [ABSTRACT FROM AUTHOR]

A green strategy was developed for the synthesis of various value-added chemicals using methanol, acetonitrile, acetic acid, acetone and ethyl acetate as the hydrogen source by coupling them with olefins over heterogeneous photocatalysts. A radical coupling mechanism was proposed for the hydrofunctionalization of olefins with methanol to higher aliphatic alcohols over the Pt/TiO2 catalyst as the model reaction. C–H bond cleavage and C–C bond formation between photogenerated radicals and terminal olefins were accomplished in a single reaction at high efficiency. Our approach is atomically economical with high anti-Markovnikov regioselectivity and promising application potential under mild reaction conditions. [ABSTRACT FROM AUTHOR]

The Fischer-Tropsch to olefins (FTO) process is a promising alternative non-petroleum route to produce value-added olefins. In this study, Co 2 C nanoprisms formed via the CoMn spinel structure were used as the active phase for the FTO reaction and the product distribution was thoroughly investigated. A break from the traditional ASF model was found with much lower methane selectivity than that predicted by the ideal ASF law. In addition, the as-obtained hydrocarbons were mainly concentrated in the range of C 2 to C 12 with the C 2-12 selectivity as high as 91% while the C 13+ selectivity as low as 5%, indicating a much narrower distribution, which was rarely observed in the FT reaction. Moreover, ∼86% of the hydrocarbon products were olefins with very high olefin to paraffin ratios, suggesting a promising route for the selective production of olefins directly from syngas. A modified ASF distribution model was proposed with three different chain growth probabilities to rationalize the non-ASF phenomenon. [ABSTRACT FROM AUTHOR]

Direct production of lower olefins (C 2 = −C 4 = : ethylene, propylene and butylene), basic carbon-based building blocks, from carbon dioxide (CO 2 ) hydrogenation is highly attractive, although the selectivity towards olefins has been too low. Here we present a series of bifunctional catalysts contained indium-zirconium composite oxides with different In:Zr atomic ratios and SAPO-34 zeolite, which can achieve a selectivity for C 2 = –C 4 = as high as 65–80% and that for C 2 –C 4 of 96% with only about 2.5% methane among the hydrocarbon products at CO 2 conversion of 15–27%. The selectivity of CO via the reverse water gas shift reaction is lower than 70%. The product distribution is completely different from that obtained via CO 2 -based Fischer-Tropsch synthesis and deviates greatly from the classical Anderson-Schulz-Flory distribution. The zirconium component plays a critical role in determining the physicochemical properties and catalytic performance of bifunctional catalysts. Catalyst characterization and density functional theory calculations demonstrate that the incorporation of a certain amount of zirconium can create more oxygen vacancy sites, stabilize the intermediates in CO 2 hydrogenation and prevent the sintering of the active nanoparticles, thus leading to significantly enhanced catalytic activity, selectivity of hydrocarbons and stability for direct CO 2 hydrogenation to lower olefins at the relatively high reaction temperature of 380 °C. [ABSTRACT FROM AUTHOR]

Abstract: A mild strategy to form ethylene glycol via photocatalytic C-C coupling of methanol and formaldehyde was developed with high atomic efficiency over M/TiO2 under UV-light irradiation. The presence of both methanol and formaldehyde significantly enhanced the formation of ethylene glycol with selectivity of 80%. A radical reaction mechanism for the photocatalytic C-C coupling of methanol and formaldehyde into ethylene glycol was proposed based on electron spin resonance and isotope labeling experiment as well as quantum chemical calculations.Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of CoMn catalysts derived from hydrotalcite precursors with different Co/Mn molar ratios were prepared and applied for higher alcohols synthesis (HAS) via syngas. The physical and chemical properties of as-prepared catalysts were investigated by various characterization methods such as BET, XRD, TPR, TG, SEM, HRTEM and EDS. The results showed that the proper Co/Mn molar ratio can increase the specific surface area, improve the reducibility, and form regular layered structure to provide more uniform distribution of active sites, thereby enhancing the catalytic activity and alcohol selectivity. When the Co/Mn ratio of catalyst reached 2, the highest space time yield (STY) and selectivity of alcohol were obtained. Moreover, the CoMn catalyst with layered structure showed higher activity and yield of alcohol under high reaction temperature than that without layered structure. Characterization results indicated that the layered structure catalyst can provide larger surface area, smaller particles size, and stronger interaction between Co and Mn, as well as resist the separation of Co, Mn and prevent the aggregation, thus improving the catalytic performance of CoMn catalysts for higher alcohols synthesis. In addition, the CoMn catalyst obtain derived from hydrotalcite precursors presented great stability for keeping active site highly disperse on the layer during the long reaction time. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis (FTS) is a structure-sensitive reaction for sustainable production of green fuels and value-added chemicals via syngas derived from coal, biomass, shale gas and natural gas. The nanostructure of a Fischer-Tropsch (FT) catalyst plays a crucial role in its catalytic performance. This review summarizes recent advances in the investigation of nanoeffects of FT catalysts, especially the effects of the active phase, particle size and exposed facet on catalytic performance. Perspectives and challenges for further research in nanocatalysis for syngas conversion are also given. [ABSTRACT FROM AUTHOR]

A series of TiO 2 supported Co–Cu catalysts with the weight percent of potassium oxides ranged from 0 to 3.5 wt.% were synthesized. This work investigates the influence of potassium promoter on CO 2 hydrogenation to long-chain (C 5+ ) hydrocarbons. The introduction of suitable amount of K into the CoCu/TiO 2 catalyst remarkably promoted the formation of C 5+ hydrocarbons and suppressed methane formation. The temperature-program desorption measurements demonstrate that the addition of K increases the chemisorption of CO 2 , whereas H 2 adsorption is decreased, which enhanced production of liquid fuels. However, these effects were not obvious with the addition of excess amount of K due to the slight change of surface K content. A maximum C 5+ yield with CO 2 conversion of 13% and C 5+ selectivity of 35.1 C-mol% is obtained over the CoCu/TiO 2 catalyst with 2.5 wt.% of potassium promoter loading, which also exhibits a substantial stability. [ABSTRACT FROM AUTHOR]

Abstract: Highly stable SiO2-coated multiple CuFe nanoparticles (CuFe@SiO2) were prepared by combining a facile thermal decomposition and the reverse microemulsion method. In the test of CO hydrogenation for higher alcohols synthesis (HAS), it was found that the prepared CuFe@SiO2 catalyst showed higher CO conversion, C2+OH selectivity and a superior stability than those of CuFe catalyst with time on stream. This could be related to the space confined effect of the core-shell structure that inhibited the sintering and phase separation of the Cu-χ-Fe5C2 phase, known as the dual active sites for alcohols formation, which inherently improved the catalytic performance of the sample. Furthermore, the correlation between the catalytic performance and the structural evolution was also discussed.Graphical Abstract: The CuFe@SiO2 catalysts maintained the Cu-χ-Fe5C2 dual active sites without sintering and phase separation, and thus showed the higher and superior stable C2+OH selectivity. [ABSTRACT FROM AUTHOR]

Highly dispersed FeMn nanoparticles were encapsulated with a carbon layer to form a core–shell structure. This catalyst (FeMn@C) exhibited distinguished catalytic activity, high light-olefin selectivity (40.6%) and superior stability in the Fischer–Tropsch synthesis. Furthermore, it was revealed that the carbon layer facilitated the formation of χ-Fe5C2 with suitable particle size, which is responsible for the enhanced catalytic activity. In particular, the core–shell structure of FeMn@C could also influence the distribution of hydrocarbons and the catalyst stability due to the confinement effect. [ABSTRACT FROM AUTHOR]

CoMn model catalysts were prepared by co-precipitation and evaluated for higher alcohol synthesis (HAS) via syngas. The selectivity to oxygenates (mainly alcohols and aldehydes) was found to be higher than 20 C% for the Na-promoted CoMn catalyst. Among the oxygenates, C 2+ and C 6+ fractions accounted for >90 wt% and ∼50 wt%, respectively. Metallic Co 0 particles and MnCO 3 were found in both Na-promoted and unpromoted CoMn catalysts after the reaction, whereas Co 2 C nanoparticles could only be observed in the spent Na-promoted catalyst. The addition of Na benefited the carbonization of cobalt and increased the selectivity to oxygenates and CO 2 . Our studies thus suggested that Co/Co 2 C were the bifunctional dual-sites for the oxygenates formation over the Na-promoted CoMn catalyst, where Co catalyzed CO dissociation and chain propagation, while Co 2 C was responsible for CO non-dissociative activation and subsequent insertion. In addition, the sole Co 2 C nanoparticles with certain exposed facets may also act as another kind of active dual-sites for oxygenates formation. [ABSTRACT FROM AUTHOR]

A series of hollow MnOx-CeO 2 mixed oxide catalysts were prepared by employing carbon as hard templates. The activity tests reveal that the catalytic performance of MnOx-CeO 2 (CS) samples are more active than that of MnOx-CeO 2 (AC) sample, indicating carbon sphere (CS) as a more effective carbon template. Among these samples, MnOx-CeO 2 (CS1) sample exhibits the best activity, for which a maximal NO conversion (∼82%) could be attained at 220 °C when GHSV = 120,000 h −1 . In addition, the NO conversion could be further improved with lower NO initial concentration or higher O 2 content. Under the simulated flue gas condition, the activity of MnOx-CeO 2 (CS1) sample is barely affected by the presence of CO 2 , but the influence of H 2 O and SO 2 couldn’t be neglected. The characterization result proves that the core-shell hollow structure has been successfully synthesized over MnOx-CeO 2 binary oxides. For the hollow MnOx-CeO 2 sample, the mesopore structures are formed and the MnOx oxides are highly dispersed on CeO 2 support. Among these samples, MnOx-CeO 2 (CS1) sample possesses the largest S BET and V total values. The result of H 2 -TPR and oxygen pulse measurement indicates that MnOx-CeO 2 (CS) samples, especially MnOx-CeO 2 (CS1) exhibits the best redox property. Moreover, more amount of high valence Mn as redox active sites and more oxygen vacancies exist in MnOx-CeO 2 (CS1) proved by XPS technique. Overall, these properties may contribute to the excellent activity. [ABSTRACT FROM AUTHOR]

A series of Co/ SiO2 catalysts with different sodium (Na) loadings (0, 0.1, 0.2, 0.5 and 1 wt%) were prepared and evaluated for Fischer-Tropsch reaction to study the effect of Na on the catalyst structure and catalytic performance. The addition of Na was found to decrease the catalytic activity and hydrocarbon selectivity, but increase CO2 selectivity due to the enhanced WGS activity. The addition of Na also resulted in higher selectivity to oxygenates (alcohols and aldehydes) and O/P ratio as well as the shift of hydrocarbons to lower carbon numbers. Structure characterization revealed a decrease in the surface area and particles size for the calcined samples with the addition of Na. Co2C was formed during the reaction process for the Na-promoted catalysts. As a result, a new Co/ Co2C bifunctional active sites were generated for oxygenates formation leading to increasing oxygenates selectivity. In addition, the Co2C nanoparticles alone may also act as dual active sites for oxygenate formation at high reaction pressure over the promoted catalysts with high Na loading. [ABSTRACT FROM AUTHOR]

A series of industrial related Cu/ZnO/AlO methanol catalysts with different compositions were prepared by parallel coprecipitation method at neutral condition. The structural properties were characterized through BET, XRD, TEM, TPD and TPR, and the catalytic performances were evaluated on a 4-tube stainless steel continuous flow fixed-bed microreactor. The influence of composition on performances was investigated. The results show that AlO increases the long-term stability of catalysts due to stabilizing effect, meanwhile, Al also promotes the formation of zincian malachite phase as the precursor during coprecipitation and aging. Furthermore, AlO surface acidity also affects the byproducts selectivity. Cu/Zn ratio influences the activity of catalysts which could be traced back to precursor phases. ZnO also affects the long-term stability probably derived from its spacing effect. Taking activity, long-term stability and product purity all into consideration, an optimized composition was found to be with 2.8 ≤ n(Cu)/ n(Zn) ≤ 3.0 and 10 ≤ n(Al) ≤ 12, over which the performances are better than that of commercial C307 catalyst in our experiments. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Accurate analysis of Fischer-Tropsch (FT) products is very important for reaction mechanism and kinetics studies. However, it is rather complex since many factors in collecting, measurement and GC analysis have influences on the results. These factors should be considered in research to avoid possible artifacts. In this paper, some issues and considerations in FT products analysis were discussed. To obtain reliable results, it is recommended to collect samples after the steady state of the reaction reached without further catalyst reconstruction and net products accumulation. Products collection fraction should be in acceptable range besides commonly calculated balances. The physical separation of different phases of products should be as complete as possible and the identification of different products in GC analysis should be checked carefully. Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of Cu–Zn–Al–Zr precursor materials are prepared by coprecipitation at different pH values (6.0–11.0) and treated under hydrothermal condition. Zincian malachite is formed as the main phase at the low pH of 6.0 and 7.0, and is replaced by hydrotalcite-like phases with increasing the pH. After calcination and reduction of precursors, Cu/ZnO/Al 2 O 3 /ZrO 2 catalysts are obtained and tested for methanol synthesis from CO 2 hydrogenation at the reaction temperature of 463 K. With increasing pH, the Cu particle size first increases until pH 9.0 and then decreases. Compared with the sample resulting from well-crystallized zincian malachite (pH 7.0), the catalysts derived from phase-pure hydrotalcite-like precursors (pH ≥ 9.0) exhibit lower BET specific surface area and lower specific Cu surface area. In addition, due to the smaller of Cu particle size and the stronger interaction among Cu and ZnO, the catalytic activity for the Cu/ZnO/Al 2 O 3 /ZrO 2 catalysts via the hydrotalcite-like precursors is higher than that for the catalysts derived from zincian malachite precursors at low reaction temperature. A maximum CH 3 OH yield of 0.087 g gcat −1 h −1 with the CO 2 conversion of 10.7% and the CH 3 OH selectivity of 81.8% at 463 K and 5.0 MPa is obtained over the Cu/ZnO/Al 2 O 3 /ZrO 2 catalyst prepared at pH 9.0. [ABSTRACT FROM AUTHOR]

The core–shell catalysts with Cu and Cu/ZnO nanoparticles coated by mesoporous silica shells are prepared for CO 2 hydrogenation to methanol. With the confined effect of silica shell, the size of Cu nanoparticles is only about 5.0 nm, which results in high activity for CO 2 conversion. The CH 3 OH selectivity is enhanced significantly with the introduction of ZnO. The core–shell structured catalysts endow the Cu nanoparticles trapped inside with excellent anti-aggregation and no deactivation is observed with time-on-stream. Therefore, the core–shell Cu/ZnO@m-SiO 2 catalyst exhibits the maximum CH 3 OH yield with high stability. [ABSTRACT FROM AUTHOR]

Controlling product selectivity still remains as a grand challenge for syngas conversion to fuels and chemicals. Herein, ZnO modified CoMn-based catalysts were prepared for direct higher oxygenates synthesis via syngas conversion, and the role of Zn promoter on catalytic behaviour and structure evolution was investigated comprehensively. It was found that the addition of Zn greatly reduced the particle size of active phases including Co and Co 2 C. Specially, the Zn promoter facilitated the formation of Co 2 C species, thus effectively tuning the surface ratio of Co/Co 2 C and strengthening the function for CO associative adsorption and insertion for oxygenates product formation. As a result, the oxygenates selectivity was enhanced to 39.1 wt% over ZnO-promoted CoMn-based catalyst, where more than 96.0 wt% of the produced oxygenates are C 2+ products. In addition, Zn promoter can weaken the chain growth ability, leading to the increase of low carbon chain products. [Display omitted] • The addition of Zn promoter greatly reduced the particle size of Co and Co 2 C. • Zn promoter facilitated the formation of Co 2 C. • CO associative adsorption was strengthened for oxygenates formation with Zn addition. • The selectivity of oxygenates was enhanced to 39.1 wt% for Zn-promoted CoMn-based catalyst. [ABSTRACT FROM AUTHOR]

Tuning Fischer-Tropsch synthesis products of metallic Co-based catalysts from paraffins to value-added olefins chemicals attracts great attention but remains challenging. Herein, we succeed in designing the carbon layers confined cobalt metal core-shell nanocatalyst (Co@C) via a reduction-carburization-pyrolysis (RCP) pretreatment of Co/SiO 2 , which exhibits highly efficient for Fischer-Tropsch to olefins (FTO) with negligible Water-Gas-Shift activity. At 250 °C and 5 bar, 56.4 % of olefins selectivity and limited CO 2 selectivity (5.8 %) are achieved for Mn-promoted Co@C nanocatalyst with at least 200 h of stability running. The electronic effect of carbon layers and Mn promoter as well as the confinement structure tailor the local chemical environment and weaken the hydrogenation ability of Co metal sites, thus improving the selectivity toward olefins while largely reducing the formation of CH 4 and CO 2. This work develops an effective strategy for the rational design of highly active and stable metallic Co-based FTO catalysts with high carbon efficiency. [Display omitted] • Carbon layers encapsulating Co metallic nanoparticles (Co@C) was successfully designed. • Reduction-carburization-pyrolysis (RCP) strategy was effective in fabricating Co@C structure. • Co@C nanocatalyst was favorable for olefins production instead of paraffins during FTS process. • Features of negligible WGSR activity and high carbon efficiency were observed for Co@C nanocatalyst. • Both electronic effect of carbon layers and Mn promoter could weaken hydrogenation ability of Co metal. [ABSTRACT FROM AUTHOR]

Changes in catalytic performance and catalyst structural evolution during the deactivation of the CuCo/TiO 2 model catalyst for higher alcohol synthesis via syngas were investigated. The catalytic activity decreases continuously with time-on-stream, although there is no obvious change in total alcohol selectivity. Meanwhile, the products shift gradually to low carbon number, and the chain growth probabilities of both alcohols and hydrocarbons decrease with reaction time. Using ethane hydrogenolysis as the probe reaction, the catalytic activity also declines with time-on-stream, indicating the decrease in the number of surface metallic cobalt ensembles. To elucidate the structural evolution of the catalyst, the calcined, reduced, and used catalysts were analyzed by various techniques. The bulk crystalline phase of the calcined catalyst is CuCo composite oxide, with small CuO nanoparticles spreading on the catalyst surface. After reduction, the oxides are transformed into CuCo alloy and Cu nanoparticles. For the used sample, severe sintering occurs and Co x C forms on the catalyst surface, both of which reduce the number of surface Co atoms and leads to catalytic deactivation. [ABSTRACT FROM AUTHOR]