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CO2/H2 mixtures can be directly converted into long-chain hydrocarbons with a yield of 26.7% over a bimetallic FeCo catalyst via strengthening the reinforced chain growth reaction.

This research aims to investigate steam biomass gasification in a pilot horizontal gasifier using rubber wood pellets (RWPs) and eucalyptus wood chips (EWCs) for producing syngas with an H

The highly efficient multifunctional 3% Y–Zn0.02Zr0.02/Si-beta catalyst possessed superior butadiene selectivity and ethanol conversion in direct conversion of aqueous ethanol into butadiene.

Ethanol, as one of the important bulk chemicals, is widely used in modern society. It can be produced by fermentation of sugar, petroleum refining, or conversion of syngas (CO/H

The design and construction of advanced functional structures for photocatalysts has been proven to be an extremely effective approach to greatly enhance their properties toward higher solar-driven water splitting efficiency. Here, three ZnCdS derivatives with photocatalytic performance and structure differences are constructed through C6CoK3N6 inducing and NH3·H2O etching. And the three derivatives present huge gap in structure. In comparison with ZnCdS bulk, both flake-bulk ZnCdS cage and hollow ZnCdS particle cage exhibit specific surface area about three times larger than it. Interestingly, their optical properties and band structures showcase clearly visible difference, and their band structures display a stepped distribution. These nother expressions in structure-performance strongly reflect that chemical compositions, structural traits, and the electronic properties of the Prussian blue (PB) and its analog (PBA) materials can be tailored by external stimulus. More importantly, NH3·H2O etched hollow ZnCdS particle cage by removing Co species exhibits more excellent photocatalytic hydrogen evolution activities compared with other two derivatives, and the hydrogen evolution rate reached approximately 23 mmol•g-1 h-1 under 300 W Xenon lamp irradiation with a light power of about 514 mW•cm-2. The improved photocatalytic performances mainly depend on these advantages that enriched active sites, shortened charge-migration distance, enlarged surface area, derived more charge transfer channels, and reduced reaction overpotential.

In2O3 hollow hexagonal prisms are combined with CdS–MoS2 dumbbell electrostatic self-assembly to weaken the surface oxidation kinetics. MoS2 promotes the CdS–In2O3 S-scheme heterojunction photocatalyst to show significant photocatalytic performance.

Prussian blue analogs (PBAs) are the oldest artificial cyanide-based coordination polymers similar to metal–organic frameworks (MOFs) in structure, composition, and physicochemical properties.

Directly converting CO2 into carbon-based fuels is an alternative route to produce valuable fuels.

As a part of photocatalytic water splitting, the design of low-cost, high-activity catalysts plays an essential role in the development of photocatalytic water splitting. Metal oxides have the advantages of a wide range of sources, many varieties, and easy preparation. Doping engineering on their surface can construct new active sites and adjust their catalytic activity. In this work, a new strategy was developed through anion hybridization to regulate electron delocalization. Using one of the cobalt-based zeolitic imidazole skeletons (ZIF-67) as a precursor material, a two-step calcination method was used to prepare a P-doped Co3O4 mixed anion composite photocatalyst. The hydrogen production rate of P@Co3O4 is 39 times that of ZIF-67 and 6.8 times that of Co3O4. Through density functional theory (DFT) calculations, the electron delocalization state of the sample surface is predicted and the reaction energy barrier is reduced to promote the process of the hydrogen evolution reaction (HER). The special O(δ-)-Co(δ+)-P(δ-) surface bonding state promotes the bridging of isolated electronic states and provides active sites for the adsorption and activation of reaction substrates. The improved electron transport pathway and the synergy between the catalytic sites under the high electron transport rate are the main reasons for the enhanced photocatalytic hydrogen evolution activity. This strategy, including changing the surface bond state and optimizing the structure and composition of the catalyst not only provides a new method for preparing other MOF-derived nanomaterials with porous structures but also inspires the reasonable development of other MOF-based advanced photocatalysts.

The Fischer-Tropsch (FT) synthesis, as an alternative route to produce high-quality liquid fuels and chemicals, has received considerable attention in recent years. In this work, a nano-sized capsule catalyst (ZrO2@FeCu) with ZrO2 as a core and FeCu bimetallic oxide as a shell was fabricated by urea hydrolysis method. For comparison, FeCu@ZrO2 capsule catalyst was synthesized by the sequential precipitation method. FeCu + ZrO2 reference catalyst was obtained by physically mixing of FeCu and ZrO2 samples. Besides, these catalysts with potassium (K) modification were realized by wetness impregnation method, and the catalysts are denoted as ZrO2@FeCu-K, FeCu@ZrO2-K, and FeCu + ZrO2-K, respectively. The structure-function relationship of the obtained catalysts was systematically clarified by means of a series of characterization techniques, such as BET, XRD, H2-TPR, CO-TPD, XPS, SEM and EDS mapping. Among these catalysts after reduction, ZrO2@FeCu-K exhibited the most excellent catalytic performance with 97 % CO conversion and 49 % α-olefins selectivity by promoted CO adsorption.

Catalytic conversion of CO

Up to now, the member of zeolite family has expanded to more than 230. However, only little part of them have been reported as catalysts used in reactions. Discovering potential zeolites for reactions is significantly important, especially in industrial applications. A carbonylation zeolite catalyst Al-RUB-41 has special morphology and channel orientation. The 8-MR channel of Al-RUB-41 is just perpendicular to its thin sheet, making a very short mass-transfer distance along 8-MR. This specific nature endows Al-RUB-41 with efficient catalytic ability to dimethyl ether carbonylation reaction with beyond 95% methyl acetate selectivity. Compared with the most widely accepted carbonylation zeolite catalysts, Al-RUB-41 behaves a much better catalytic stability than H-MOR and a greatly enhanced catalytic activity than H-ZSM-35. A space-confined deactivation mechanism over Al-RUB-41 is proposed. By erasing the acid sites on outer surface, Al-RUB-41@SiO2 catalyst achieves a long-time and high-efficiency activity without any deactivation trend.

Light olefins (C2–C4) are fundamental building blocks for the manufacture of polymers, chemical intermediates, and solvents. In this work, we realized a composite catalyst, comprising MnxZry oxides and SAPO-34 zeolite, which can convert syngas (CO + H2) into light olefins. MnxZry oxide catalysts with different Mn/Zr molar ratios were facilely prepared using the coprecipitation method prior to physical mixing with SAPO-34 zeolite. The redox properties, surface morphology, electronic state, crystal structure, and chemical elemental composition of the catalysts were examined using H2-TPR, SEM, XPS, XRD, and EDS techniques, respectively. Tandem reactions involved activation of CO and subsequent hydrogenation over the metal oxide catalyst, producing methanol and dimethyl ether as the main reaction intermediates, which then migrated onto SAPO-34 zeolite for light olefins synthesis. Effects of temperature, pressure and reactant gas flow rate on CO conversion and light olefins selectivity were investigated in detail. The Mn1Zr2/SAPO-34 catalyst (Mn/Zr ratio of 1:2) attained a CO conversion of 10.8% and light olefins selectivity of 60.7%, at an optimized temperature, pressure and GHSV of 380 °C, 3 MPa and 3000 h−1 respectively. These findings open avenues to exploit other metal oxides with CO activation capabilities for a more efficient syngas conversion and product selectivity.

The effects of crystallite size on the physicochemical properties and surface defects of pure monoclinic ZrO2 catalysts for isobutene synthesis were studied. We prepared a series of monoclinic ZrO2 catalysts with different crystallite size by changing calcination temperature and evaluated their catalytic performance for isobutene synthesis from syngas. ZrO2 with small crystalline size showed higher CO conversion and isobutene selectivity, while samples with large crystalline size preferred to form dimethyl ether (DME) instead of hydrocarbons, much less to isobutene. Oxygen defects (ODefects) analyzed by X-ray photoelectron spectroscopy (XPS) provided evidence that more ODefects occupied on the surface of ZrO2 catalysts with smaller crystalline size. Electron paramagnetic resonance (EPR) and ultraviolet–visible diffuse reflectance (UV–vis DRS) confirmed the presence of high concentration of surface defects and Zr3+ on m-ZrO2-5.9 sample, respectively. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) analysis indicated that the adsorption strength of formed formate species on catalyst reduced as the crystalline size decreased. These results suggested that surface defects were responsible for CO activation and further influenced the adsorption strength of surface species, and thus the products distribution changed. This study provides an in-depth insight for active sites regulation of ZrO2 catalyst in CO hydrogenation reaction.

Converting syngas into ethanol (EtOH) is highly attractive but remains challenge. Dimethyl ether (DME) carbonylation with CO to methyl acetate (MA) on zeolite and its further hydrogenation to EtOH on Cu-based catalyst open a new EtOH synthesis route from syngas. In this work, a nano-sized ZSM-35 (NZ35) zeolite, possessing abundant active sites and porosity and short diffusion path, is found to realize much better activity of DME to MA than that of the conventional ZSM-35 zeolite (CZ35). In addition, a simple formic-acid-assisted solid-state method is employed for preparation an auto-reduced CuZnAl (CZAargon) catalyst under argon atmosphere. The prepared CZAargon catalyst exhibits an excellent catalytic activity for conversion of produced MA to EtOH. By investigating the effects of different integration manners of NZ35 zeolite and CZAargon catalyst, we find that EtOH can be synthesized only when the NZ35 zeolite and CZAargon catalyst pack in a dual-catalyst bed reactor. After optimizing the reaction conditions for EtOH synthesis with the combination of NZ35 zeolite and CZAargon catalyst, it is found that the DME conversion and MA selectivity are stabilized at 47.0 % and 45.6 % respectively, at 220 °C and 2.5 MPa.