Recent advances in bifunctional catalysis for conversion of syngas and hydrogenation of CO2 into chemicals and fuels have been highlighted.

Wang and colleagues successfully designed a powerful bifunctional catalyst composed of Zn-doped ZrO 2 nanoparticles and zeolite H-ZSM-5 for one-step conversion of syngas into aromatics. Aromatics with 80% selectivity were obtained at 20% CO conversion. No catalyst deactivation was observed in 1,000 hr. Methanol and dimethyl ether were formed as reaction intermediates on Zn-doped ZrO 2 , which were subsequently transformed into aromatics on H-ZSM-5 via olefins. This work offers a highly selective and stable non-petroleum route for the synthesis of aromatics.

Bifunctional catalysis coupling CO 2 to methanol and methanol to hydrocarbons is a promising strategy for the direct hydrogenation of CO 2 into high-value chemicals. However, bifunctional catalysts suffer from low productivity due to the inertness of CO 2 and high activation energy of C−C coupling. Herein, we report a highly active bifunctional catalyst consisting of a ZnO-ZrO 2 aerogel and zeolite H-ZSM-5 for the hydrogenation of CO 2 into aromatics with 76% selectivity at a singlepass CO 2 conversion of 16%. The selectivity of CH 4 is lower than 1% at the same time. The space−time yield of aromatic hydrocarbons is as high as 0.24 g g oxide −1 h −1 under the reaction conditions of 340 °C and 40 bar over ae-ZnO-ZrO 2 /H-ZSM-5 catalyst, which outperforms the previously reported catalysts, including modified Fischer−Tropsch catalysts. We demonstrate that the ZnO-ZrO 2 aerogel catalyst, which is prepared by a combined sol−gel and subsequent supercritical drying method, not only possesses high surface area but also provides large amounts of oxygen vacancies. The formation rate of the methanol intermediate over ZnO-ZrO 2 is dominated by the total amount of oxygen vacancies. Moreover, the stable performance of the bifunctional catalyst under industrially relevant conditions suggests promising prospects for industrial applications.

Zn–ZrO2/SSZ-13 catalyzed direct conversion of syngas into lower olefins via methanol/DME intermediates with 77% selectivity at 29% CO conversion.

Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt‐based catalysts usually suffer from short‐term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand‐protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt–Zn clusters inside silicalite‐1 (S‐1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6–54 h−1 and specific activity of propylene formation of 65.5 molnormalC3normalH6  gPt−1 h−1 (WHSV=108 h−1) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S‐1‐H catalyst even after 13000 min on stream (WHSV=3.6 h−1), affording an extremely low deactivation constant of 0.001 h−1, which is 200 times lower than that of the PtZn4/Al2O3 counterpart under the same conditions. We also show that the introduction of Cs+ ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles.

A bifunctional catalyst composed of ZnGaO with a spinel structure and molecular sieve SAPO-34 catalyses the direct conversion of CO to C-C olefins with a selectivity of 86% and a CO conversion of 13% at 370 °C. The oxygen vacancies on ZnGaO surfaces are responsible for CO activation, forming a methanol intermediate, which is then converted into C-C olefins in SAPO-34.

Selective conversion of syngas (CO/H ) into C oxygenates is a highly attractive but challenging target. Herein, we report the direct conversion of syngas into methyl acetate (MA) by relay catalysis. MA can be formed at a lower temperature (ca. 473 K) using Cu-Zn-Al oxide/H-ZSM-5 and zeolite mordenite (H-MOR) catalysts separated by quartz wool (denoted as Cu-Zn-Al/H-ZSM-5|H-MOR) and also at higher temperatures (603-643 K) without significant deactivation using spinel-structured ZnAl O |H-MOR. The selectivity of MA and acetic acid (AA) reaches 87 % at a CO conversion of 11 % at 643 K. Dimethyl ether (DME) is the key intermediate and the carbonylation of DME results in MA with high selectivity. We found that the relay catalysis using ZnAl O |H-MOR|ZnAl O gives ethanol as the major product, while ethylene is formed with a layer-by-layer ZnAl O |H-MOR|ZnAl O |H-MOR combination. Close proximity between ZnAl O and H-MOR increases ethylene selectivity to 65 %.

Synthesis of ethanol from non-petroleum carbon resources via syngas (a mixture of H 2 and CO) is an important but challenging research target. The current conversion of syngas to ethanol suffers from low selectivity or multiple processes with high energy consumption. Here, we report a high-selective conversion of syngas into ethanol by a triple tandem catalysis. An efficient trifunctional tandem system composed of potassium-modified ZnO-ZrO 2 , modified zeolite mordenite and Pt-Sn/SiC working compatibly in syngas stream in one reactor can afford ethanol with a selectivity of 90%. We demonstrate that the K + -ZnO-ZrO 2 catalyses syngas conversion to methanol and the mordenite with eight-membered ring channels functions for methanol carbonylation to acetic acid, which is then hydrogenated to ethanol over the Pt-Sn/SiC catalyst. The present work offers an effective methodology leading to high selective conversion by decoupling a single-catalyst-based complicated and uncontrollable reaction into well-controlled multi-steps in tandem in one reactor.