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The direct CO2 Fischer–Tropsch synthesis (CO2-FTS) process has been proven as one of the indispensable and effective routes in CO2 utilization and transformation. Herein, we present a core-shell structured Na/Fe@Co bimetallic catalyst to boost CO2 conversion and light hydrocarbon (C2 to C4) selectivity, as well as inhibit the selectivity of CO. Compared to the Na/Fe catalyst, our Na/Fe@CoCo-3 catalyst enabled 50.3% CO2 conversion, 40.1% selectivity of light hydrocarbons (C2-C4) in all hydrocarbon products and a high olefin-to-paraffin ratio (O/P) of 7.5 at 330 °C and 3.0 MPa. Through the characterization analyses, the introduction of CoCo Prussian Blue Analog (CoCo PBA) not only increased the reducibility of iron oxide (Fe2O3 to Fe3O4), accelerated the formation of iron carbide (FexCy), but also adjusted the surface basic properties of catalysts. Moreover, the trace Co atoms acted as a second active center in the CO2-FTS process for heightening light hydrocarbon synthesis from CO hydrogenation. This work provides a novel core-shell structured bimetallistic catalyst system for light hydrocarbons, especially light olefin production from CO2 hydrogenation. [ABSTRACT FROM AUTHOR]

Spinel-like ZnFe2O4 is tailor-made synthesized for catalyzing CO2 hydrogenation, achieving an ultra-high yield (1858.1 g kgcat−1 h−1) of full spectrum alkenes in a three-stage reactor system. This study provides rational design concepts from catalyst to equipment amelioration by combining promoter regulation and ex situ water removal, efficiently catalyzing CO2 into valuable chemical feedstocks with industrial potential. [ABSTRACT FROM AUTHOR]

A Pd/SiO2@S1@H‐ZSM‐5 capsule catalyst (Pd/SiO2–SZ) is fabricated through a dual‐layer crystal growth method with an auxiliary hydrothermal reaction. The catalyst exhibits excellent selectivity to liquefied petroleum gas (LPG) in CO2 hydrogenation reactions, which is attributed to the tandem reactions of methanol synthesis on the Pd/SiO2 core catalyst and methanol dehydration to hydrocarbons on the H‐ZSM‐5 shell. The Pd/SiO2–SZ capsule catalyst has a similar mesoporous structure, narrow range of Pd particles size distribution, and consistent reduction characteristics to the Pd/SiO2 core catalyst. It maintains the physical and chemical properties of the core catalyst throughout the H‐ZSM‐5 shell synthesis process. Energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy results reveal that the H‐ZSM‐5 zeolite shell completely encapsulates the Pd/SiO2 core catalyst. Compared with the crushed capsule catalyst (Pd/SiO2–SZP), the well‐defined‐structured Pd/SiO2–SZ catalyst has a much higher LPG selectivity of 33.6 %, owing to the well‐matched reactions at the Pd/SiO2 core and H‐ZSM‐5 shell. [ABSTRACT FROM AUTHOR]

Zeolite A with different pore sizes (3 A, 4 A and 5 A) were selected as supports for preparing a series of cobalt catalysts through wetness impregnation method, using NaBH4 as an in‐situ reducing agent, but without further reduction. X‐ray photoelectron spectra (XPS) confirmed the reduction of cobalt. Transmission electron microscopy (TEM) images revealed that the cobalt nanoparticles were formed evenly on the zeolite structure by our rapid synthesis method. The catalytic activity of the prepared catalysts was investigated for the hydroformylation of 1‐hexene. Benefiting from the spatial confinement effect derived from the unique topology structure of zeolite A and the low temperature in‐situ reduction contributed by NaBH4, the conversion of 1‐hexene to C7 aldehyde with a significantly enhanced normal heptanal selectivity (normal/iso ratio of 1.93) was achieved. The present study provides a rapid and effective way for the synthesis of zeolite supported cobalt catalysts for the hydroformylation of 1‐hexene. [ABSTRACT FROM AUTHOR]

As a century‐old classical reaction, Fischer‐Tropsch (F‐T) synthesis is undergoing new developments especially in its applications of producing jet fuel, olefins, aromatics and oxygenated chemicals, which are completely different from the conventional F‐T product, gasoline, diesel and wax. Producing above new products is not obeying famous ASF distribution law, requiring revolutionary design of new F‐T catalysts and reaction pathways. A mass of new research directions on F‐T synthesis for these liquid fuels and high‐value chemicals are successfully proposed. This review spotlights recent new advances based on F‐T synthesis for non‐automotive applications, and discusses its new possible directions in future. Going beyond cars: This Minireview spotlights recent new advances based on Fischer‐Tropsch synthesis for non‐automotive applications, such as jet fuel, olefins, aromatics and oxygenated chemicals, which are completely different from the conventional Fischer‐Tropsch product, and discusses its new possible directions in future. [ABSTRACT FROM AUTHOR]

Jet fuel is not easy to synthesize by the biomass-to-liquid (BTL) process owing to the limitation of the Anderson-Schulz-Flory (ASF) hydrocarbon distribution law in Fischer-Tropsch synthesis (FTS) with biomass-derived syngas (CO+H2). Here, we realized an anti-ASF distribution to selectively produce jet fuel from biomass on a large scale by addition of small amounts of 1-olefin, a FTS product, into syngas, enhancing jet fuel selectivity in hydrocarbons up to 64% and that in oil product to as high as 91%. The Co/SiO2 catalyst (300 g) was loaded into a flow-type three-phase reactor and 120h continuous operation was conducted by using the real-time on-line biomass- derived syngas from an entrained bed gasifier of biomass (240 kgday-1) of Mitsubishi Heavy Industries, Ltd. The production rate of liquid oil reached 720 gkgcat -1h-1. The structure of the fresh and used catalyst was characterized in detail, accompanied with lab-scale data on reaction performance and catalyst properties. The stable technology process from biomass gasification to FTS, stable catalyst structure, and novel design of 1-olefin addition are the key to success in selectively converting biomass to jet fuel on a large scale. [ABSTRACT FROM AUTHOR]

A hierarchically spherical Co based zeolite catalyst with aggregated nanorods structure (simplified as Co/AN-Z) was prepared by an in-situ self-assembly crystallization route of Co/SBA-15 under hydrothermal synthesis environment. The obtained Co/AN-Z catalyst with uniformly sized zeolite microspheres with 0.5–1 μm was evaluated for improved Fischer–Tropsch synthesis (FTS) reaction activity and isoparaffin selectivity. The selectivities of isoparaffin and C 5-11 hydrocarbons were higher with a narrower product distribution as well as CH 4 and C 12+ selectivities were lower on the Co/AN-Z catalyst than those on the commercial HZSM-5 supported Co catalyst (Co/HZSM-5) for FTS reaction. The demonstrated route of the hierarchically spherical Co based zeolite catalyst can be extended to synthesize bifunctional catalyst and expected to find a new approach for tandem reaction. [ABSTRACT FROM AUTHOR]

In this paper, a new Co/ZrO 2 –SiO 2 catalyst with specific bimodal structure was developed and applied for jet fuel direct synthesis from syngas in Fischer–Tropsch synthesis (FTS) with varied 1-olefins as additives. In a slurry-phase reaction process, 1-olefins as additives were introduced into reaction system to enhance the selectivity of jet-fuel-like hydrocarbons (C 8 –C 16 ), at the same time suppressing the formation of light hydrocarbons including CH 4 and CO 2 . The new FTS reactions, due to the co-fed 1-olefins, showed anti-Anderson–Schulz–Flory (anti-ASF) law product distribution. Among all the co-fed mixed 1-olefins, 1-decene and 1-tetradecene mixed with the volume ratio of 1:1, exhibited the highest selectivity of jet-fuel-like hydrocarbons. This new Co/ZrO 2 –SiO 2 bimodal catalyst had specific bimodal structure, which realized its excellent catalytic performances in the FTS reaction, because the large pores provided efficient pathways for reactants and products diffusion, and high metal dispersion was obtained by the newly formed small pores with enhanced active surface area. [ABSTRACT FROM AUTHOR]

A two-step method consisting of acid leaching and base leaching was developed and applied to create hierarchical pores on a general microporous Y zeolite. Characterization with BET and TEM on the texture, morphology and structure of the prepared hierarchical Y zeolite confirmed the co-existence of mesopores with zeolitic walls. The analysis results showed that the mesopore surface area and pore volume of the hierarchical zeolite Y (Y-AB x , A: acid leaching, B: base leaching, “ x ” represents for base leaching time) increased with increasing the base leaching time. The hierarchical zeolite Y supported Co as catalysts were employed to catalyze the hydrogenation of carbon monoxide to form hydrocarbons through Fischer–Tropsch synthesis (FTS) reaction. The CO conversion and C 5 – 11 selectivity on Co/Y-AB x catalysts increased significantly compared with those on the pristine Y supported Co catalyst. The isoparaffin selectivity of Co/Y-AB4 catalyst reached up to 52.3% and middle hydrocarbons became the main FTS products due to the optimized hydrocracking and isomerization function afforded by the hierarchical zeolite Y with the strong Brønsted acid/Lewis acid (B/L) ratio and textural property. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two new methods are presented for zeolite capsule catalyst preparation. [•] One is an improved hydrothermal synthesis process. [•] Another is an initially reported method without employing hydrothermal synthesis. [•] Zeolite capsule catalysts realize tandem catalytic synthesis with higher efficient. [ABSTRACT FROM AUTHOR]

Highlights: [•] We realize the controllable encapsulation of Co clusters inside CNTs channels. [•] The oxygen-containing functional groups are selectively removed. [•] The cobalt nanoparticles inside the CNTs channel reach up to 80%. [•] The Co/CNTs-650 catalyst exhibits high activity and C5+ selectivity. [ABSTRACT FROM AUTHOR]

Abstract: A well-designed zeolite capsule catalyst with a Core (Fe/SiO2)-Shell (Silicalite-1) structure was successfully prepared by zeolite seeding and then zeolite shell growing via secondary hydrothermal method. The characterization on this zeolite capsule catalyst indicated that it had a compact, defect-free zeolite shell enwrapping core catalyst tightly. The application of this zeolite capsule catalyst was the direct synthesis of light alkenes from syngas via Fischer–Tropsch synthesis (FTS) reaction. This zeolite capsule catalyst exhibited excellent abilities compared with the traditional FTS catalyst, both on the controlled synthesis of the desirable light alkenes and the suppressing formation of the undesired long-chain hydrocarbons. [Copyright &y& Elsevier]

Abstract: Three kinds of H-ZSM-5 zeolite capsule catalysts were prepared on Ru/SiO2 catalyst pellets with different size. Characterization indicated that defect-free H-ZSM-5 capsule had been constructed on the Ru/SiO2 surface successfully. And small Ru/SiO2 pellet with large external surface was favorable for zeolite capsule growth under the same zeolite synthesis conditions. In the iso-paraffin direct synthesis via Fischer–Tropsch synthesis (FTS) reaction, zeolite capsule catalysts, especially the one with smaller pellet size, realized the higher iso-paraffin selectivity comparing with conventional FTS Ru/SiO2 catalyst, and physically mixed catalyst of Ru/SiO2 with H-ZSM-5 zeolite. [Copyright &y& Elsevier]

Bimodal catalyst support is a widely applied concept in solid catalysts but until now the supported metal on the bimodal support has no satisfied dispersion and the average metal particle size is generally larger than the pore size of small pores (mesopores) of the bimodal structure, lowering the power and significance of the bimodal structure. To overcome this problem, a novel ZrO 2 SiO 2 bimodal pore support with enlarged depth of small pores, was successfully fabricated though self-assembly of nanosized ZrSiO 4 inside pore of silica gel. Cobalt was finely dispersed on bimodal support by incipient-wetness impregnation. The bimodal support and catalyst were characterized by various techniques, such as BET, TEM, XRD, and TPR and H 2 -chemisorpion. The bimodal catalyst was applied in slurry-phase Fischer-Tropsch synthesis. Characterization results suggested that bimodal pore support processed larger BET surface than pristine silica gel, due to the newly formed small pores organized by packing of the ZrSiO 4 nanoparticles. The enlarged BET surface area leaded to good dispersion of cobalt species. More importantly, it was observed that the deep small pores could serve as traps for Co nanoparticles, preventing sintering and agglomeration due to confinement effect. Co/30 wt% ZrO 2 -Q-50 and Co/20 wt% ZrO 2 -Q-100 bimodal catalyst with large BET surface and deep small pores exhibited excellent catalytic activity, and selectivity to heavy hydrocarbons due to high dispersion of cobalt and unique pore structure, while coexisting ZrO 2 promoted the reduction of finely-dispersed cobalt oxide nanoparticles. It is interesting to find that different from the conventional theory where small metallic particle lowers chain-growth probability, the trapped smaller Co particles inside deep small pores achieved higher chain-growth probability due to the facilitated re-adsorption of olefinic intermediates happening inside deep small pores. [ABSTRACT FROM AUTHOR]

Hierarchical HZSM-5 zeolite with combined micropores and mesopores was synthesized by one-step approach with TPAOH and F127 as dual templates. The physical and acidic properties of the hierarchical HZSM-5 zeolite were characterized by XRD, N 2 adsorption–desorption isotherm, SEM, TEM, and NH 3 -TPD techniques. The hierarchical HZSM-5 zeolite exhibited a significantly higher mesopore surface area and larger mesopore volume than that of the conventional HZSM-5. The prepared hierarchical HZSM-5 and conventional HZSM-5 zeolite supported cobalt catalysts were evaluated via Fischer–Tropsch synthesis (FTS) reaction to tune product selectivity. Compared with the conventional catalyst, the CO conversion of FTS reaction on the present catalyst increased significantly. Meanwhile, the C 5 + selectivity and isoparaffin selectivity also increased. The C 5–11 hydrocarbons with a lot of isoparaffin and olefin had become the main FTS products due to the optimized hydrocracking and isomerization afforded by the hierarchical pore structure, different from the conventional FTS hydrocarbons which were mainly composed of normal paraffin. [ABSTRACT FROM AUTHOR]

Abstract: The different solvents were applied, such as acetic acid or ethanol, during preparation of Fischer–Tropsch synthesis (FTS) catalysts, to modify the surface properties of silica supports or as a solvent of cobalt precursors. The modification of silica supports by acetic acid or ethanol improves the reduction degree and dispersion of supported cobalt simultaneously, realizing higher catalytic activity, and the catalysts prepared from ethanol solution of cobalt precursor exhibit significant stability and activity in slurry phase FTS reaction during 100h. The obtained catalysts were characterized by XRD, TPR, in situ DRIFT and H2 chemisorption. [Copyright &y& Elsevier]

Abstract: Silica-supported cobalt (20wt%) catalysts were prepared by incipient-wetness impregnation of silica with different cobalt nitrate solutions. The catalyst prepared from dehydration ethanol solution exhibited stable and the highest activity, as well as significantly low methane selectivity. Cobalt crystalline size of the catalyst prepared from dehydrated ethanol was smaller than that of the catalyst prepared from aqueous solution, and existed two different size where the large particles showed low bulk density with cluster-like structure. But only larger clusters existed in the catalyst prepared from aqueous solution. The increased amount of active sites and more reactive adsorbed CO on the surface determined the highest activity of the catalyst prepared from dehydrated ethanol solution in liquid-phase Fischer-Tropsch synthesis (FTS) reaction. [Copyright &y& Elsevier]

Superior iron-based Fischer-Tropsch synthesis (FTS) catalysts (Fe/NMCs) were developed by impregnating high amount of iron (40 wt%) over nitrogen-rich mesoporous carbons (NMCs) with high porosities. The large pore volumes and specific surface areas of NMCs realized the high loadings and proper dispersions of iron while the nitrogen-containing groups enhanced the basicities of the catalysts. Weak metal-support interactions were observed in Fe/NMCs, which improved the reduction, carburization of iron, and further the FTS activities. FTS tests indicated a medium amount of nitrogen (≤8.3 wt%) did not show obvious effect on the activity of the catalyst, but a much higher amount of nitrogen (≥16.5 wt%) could result in a significant decrease of activity. Nitrogen-containing groups could effectively suppress the methane selectivity and improve the lower olefins selectivity in the FTS reaction. The hydrocarbon productivity of the Fe/NMCs was up to 0.62 g HC/(h·g cat.) at 260 °C, 1 MPa, and H 2 /CO ratio of 1, much higher than that of any other iron catalyst reported under similar conditions. As a result of the superior performance, Fe/NMCs could be one of ideal candidates for iron-based FTS catalysts in the future. [ABSTRACT FROM AUTHOR]

The catalysts with high activity and selectivity, especially the latter, play a key role in Fischer–Tropsch synthesis technology. Herein, a novel Fe-based confinement catalyst, Fe 2 O 3 encapsulated in TiO 2 nanotubes, was prepared by a method of vacuum-assisted impregnation. The catalyst presented an excellent yield of oil phase hydrocarbons and C 5+ selectivity due to the confinement effect. This interesting phenomenon was discussed from the view of the restrained molecular movement and enhanced readsorption of short-chain α-olefins in the confined space of TiO 2 nanotube channels. The results over this novel confinement catalyst revealed a promising research prospect on adjusting the product distribution to long-chain hydrocarbons for Fe-based Fischer–Tropsch catalyst. [ABSTRACT FROM AUTHOR]

A novel iron-based micro-capsule catalyst with interior Fe/Silica core and exterior H-ZSM-5 shell was synthesized via in-situ crystallization route on Fe/SBA-15 catalyst by using steam-assisted crystallization (SAC) process and evaluated for direct synthesis of middle isoparaffin from syngas in a fixed-bed reactor. Structure characterization indicated that the size of micro-capsule catalyst was about 1–2 μm. According to activity test results, original Fe/SBA-15 catalyst exhibited a low selectivity of isoparaffin as 8.2%. But the as-prepared micro-capsule catalyst achieved an excellent performance for isoparaffin synthesis with the selectivity up to 46.5%. Meanwhile, the physical mixture catalyst (Fe/SBA-15 and H-ZSM-5) exhibited lower isoparaffin selectivity with 33.9% than that of the micro-capsule catalyst. The spatial confinement effect of the micro-capsule catalyst played an important role for the high selectivity of isoparaffin synthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microwave assembling nitrogen-regulated graphene supported iron were fabricated. • N atom could effectively anchor iron, promoting small-size iron species formation. • The size of the iron nanoparticles could be regulated by adjusting microwave time. • Pyridinic-N and pyrrolic-N promoted the formation of alkene-rich hydrocarbons. Facile preparation of highly efficient iron-based catalysts is vital to improve the performance of Fischer-Tropsch synthesis (FTS), a sustainable process for converting non-petroleum carbon resources to valuable hydrocarbons. In this work, a convenient preparation for nitrogen-regulated graphene supported iron nanoparticles, with the assistant of microwave treatment, was developed. Thereinto, the nitrogen-containing groups in graphene support were introduced by NH 3 ·H 2 O treatment. By comparison with ordinary calcination, microwave treatment could significantly shorten the heating time to few seconds, and promote the reduction of iron species. The existence of a small number of nitrogen-containing groups could effectively anchor iron species, and improve the dispersion of iron species. Meanwhile, the duration length of NH 3 ·H 2 O treatment time could regulate the content of N configuration (pyridinic-N and pyrrolic-N). The size of supported iron species from 120 nm to 10 nm could be well controlled via increasing microwave time from 0 to 14 s. For N-regulated graphene supported iron catalysts, evenly dispersed small particles of iron species, improved surface reduction behavior and reasonable N configuration all promoted FTS. Under relevant industrial conditions (320 °C, 2.0 MPa, 5 g h mol−1), the optimized 15%Fe/AG(12 h)-W(10) catalyst achieved CO conversion as high as 97.2% and C 5+ selectivity of 40.0% while maintaining a mild CO 2 selectivity (28.2%). The superior preparation and catalytic performance disclosed that the catalyst could be one of ideal candidates for industrial iron-based FTS catalysts in future. [ABSTRACT FROM AUTHOR]

The catalytic performance of CO 2 hydrogenation to liquid fuels over a bifunctional catalyst can be efficiently enhanced via simply tuning the microenvironment properties of ZSM-5 zeolite. [Display omitted] • K-Fe/C and tailor-made ZSM-5 are coupled together for CO 2 hydrogenation. • Surface acid properties of ZSM-5 can be regulated through different ion-exchange strategies. • Alkali K+ ions are effective in reducing strong acids, boosting up C 5+ hydrocarbon selectivity. Catalytic conversion of greenhouse CO 2 into valuable chemicals or fuels is highly attractive in terms of sustainable development. The chemical inertness of CO 2 molecules and high kinetic barriers for C–C propagation hinder its efficient utilization. Here we report a bifunctional catalyst composed of K-Fe/C and zeolite that efficiently produced liquid fuels via simply tuning the microenvironment properties of ZSM-5 zeolite. The catalysts are characterized by Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), X-ray diffractometer (XRD), temperature programmed desorption (NH 3 -TPD), X-ray photoelectron spectroscopy (XPS). K-Fe/C catalyst is mainly responsible for the formation of olefins, while ZSM-5 catalyst is mainly responsible for olefin secondary reaction, such as aromatization, isomerization, and cracking reaction. Surface acid properties of ZSM-5 can be well regulated through different ion-exchange strategies (NH 4 +, K+, Na+, Mg2+, Cu2+, Cs2+, La3+, Ce2+, Mn2+), in which the strong surface acid properties of ZSM-5 are eliminated with the utilization of K+-ion exchange strategy and then it presents a high C 5+ selectivity by suppressing the light saturated hydrocarbons formation. This work provides new insights or facile catalyst treatment for the efficient production of liquid fuels from CO 2 hydrogenation via tuning surface microenvironment properties of ZSM-5 zeolite. [ABSTRACT FROM AUTHOR]

• The catalyst preparation method was wastewater-free and environmentally friendly. • The effect of oxalic acid amount on the physicochemical properties was evaluated. • The structure-performance relationship of Cu/ZnO catalysts was clarified. • Methanol itself was used as promoter during low-temperature methanol synthesis. • C 4-Red showed the maximum STY (456.3 g/kg h−1) and TOF, 11.4 × 10−3 s−1 values. Binary Cu/ZnO catalysts were prepared by solid-state method and tested for vapor-phase low-temperature methanol synthesis from CO 2 -containing syngas. The influence of H 2 C 2 O 4 /(Cu + Zn) molar ratio on the physicochemical properties and the corresponding catalytic activity was systematically studied. The space time yield (STY) of methanol exhibited a linear relationship with the Cu0 surface area, and increased linearly by enhancing the number of strongly acidic sites or moderately basic sites. The effects of various parameters on the methanol synthesis reaction were also investigated. C 4-Red catalyst (H 2 C 2 O 4 /(Cu + Zn) = 4/1) exhibited the maximum turnover frequency (TOF, 11.4 × 10−3 s−1) and STY values (456.3 g/kg h−1), due to the larger Cu0 surface area, greater specific surface area, more strongly acidic sites and moderately basic sites. The strengthened Cu-ZnO interaction, superior CO and H 2 adsorption capability as well as higher adsorbed CO and H 2 amount also contributed to increasing the catalytic performance of C 4-Red catalyst. [ABSTRACT FROM AUTHOR]

Direct Conversion of CO 2 to Aromatics via a Modified Fischer-Tropsch Synthesis Process. • Na doping in Fe-based catalyst is beneficial for alkenes synthesis from CO 2 hydrogenation. • Na modified Fe-based catalyst (Na-Fe@C) was combined with hollow acidic zeolite H-ZSM-5 for aromatics synthesis from CO 2 hydrogenation in a single pass. • The cooperative interplay between the multifunctional catalysts guaranteed the high yield of aromatics (203.8 g CH2 kg cat −1 h−1). The direct conversion of CO 2 to aromatics not only reduces carbon emissions but also provides an alternative way for value-added chemicals synthesis. Even though the hydrogenation of CO 2 to aromatics has been realized via a methanol-mediated pathway or a modified Fischer-Tropsch synthesis route, low yield of aromatics is still the bottleneck of this strategy. Here, we develop a multifunctional catalyst composed of Na modified Fe-based catalyst and hollow acidic zeolite H-ZSM-5 to catalyze the hydrogenation of CO 2 to aromatics by single pass. Na modified Fe-based catalyst prepared by pyrolysis of Fe-based metal-organic frameworks (Fe-MOFs) can boost the formation of alkenes intermediates because of its high active sites accessibility and precisely tailored catalytic interfaces. Thereafter, the produced alkenes can be converted to aromatics via the dehydrogenation and cyclization reactions when they diffuse to the acid sites of H-ZSM-5. The hollow H-ZSM-5 with short diffusional channels, appropriate density and strength of acid sites guaranteed the high yield of aromatics (203.8 g CH2 kg cat −1 h−1). Furthermore, the driving force in the tandem process can be attributed to the cooperative interplay between the multifunctional catalysts. The CO 2 adsorbed on Fe-based catalyst can be employed as acceptors for H species produced from the dehydrogenation and cyclization reactions, thereby increasing the yield of aromatics by shifting the chemical thermodynamic equilibrium. [ABSTRACT FROM AUTHOR]

We evaluate the direct CO 2 conversion to light olefins reaction via a hybrid catalyst of In 2 O 3 /ZrO 2 metallic oxide and zeolite SAPO34 components. On this catalyst, it can realize producing high light olefins selectivity of 77.59% via a direct tandem catalysis process, that is, the formed methanol on the oxygen vacancies surface of In 2 O 3 /ZrO 2 in the first step will continue passing through the SAPO34 zeolite channel, where it is changed into light olefins simultaneously. Even there are many studies focused on this tandem catalysis reaction via bi-functional catalyst in recent years, however, to reduce the poisonous byproduct CO is still in a big challenge. In this reaction, large amounts of poisonous CO will be easily formed from reverse water gas shift reaction. Therefore, in our research, by optimizing the reaction, the catalyst can suppress the undesirable CO formation obviously. It shows good potential leading to scale-up cause of the outstanding reaction performance and its friendly-environment properties. The light olefins can be efficiently synthesized on the hybrid catalyst In 2 O 3 /ZrO 2 &SAPO from CO 2 hydrogenation due to its synergistic effect, at the same time as accompanying with very low undesirable CO by-product. Unlabelled Image • Effective utilization of greenhouse gas is realized. • The light olefins is synthesized with high selectivity via a direct tandem catalysis process. • The undesirable CO formation is obviously suppressed. • The outstanding reaction performance and its friendly-environment properties show good potential for further scale-up. [ABSTRACT FROM AUTHOR]

A series of supported Fe/Co catalysts with Y zeolite-containing K, Ce or La used as support were synthesized to perform CO 2 hydrogenation to linear-alpha olefins (LAOs). Medium acid-base properties and the content of active carbide (Fe 5 C 2) are both affected by the different ion-exchange strategies and heteroatom doping used, which are crucial for the CO 2 conversion to LAOs process. CO 2 conversion (25.9%) and highest C 4+ = alkenes (45.9%), of which the formation of LAOs accounts for 78.9%, were achieved after the supported bimetallic Fe/Co-Y catalyst containing K+-exchange zeolite was used. Unlabelled Image • Supported Fe/Co-Y K was synthesized to directionally convert CO 2 hydrogenation to linear-alpha olefins. • Medium acid-base properties and the content of carbides were improved with Co doping and K+-exchanges. • Fe/Co-Y K catalyst is stable and efficient for olefins production. [ABSTRACT FROM AUTHOR]