Cobalt-Based Nonprecious Metal Catalysts Derived from Metal–Organic Frameworks for High-Rate Hydrogenation of Carbon Dioxide
2019-07-25T17:04:52Z (GMT) by
The development of cost-effective catalysts with both high activity and selectivity for carbon–oxygen bond activation is a major challenge and has important ramifications for making value-added chemicals from carbon dioxide (CO2). Herein, we present a one-step pyrolysis of metal organic frameworks that yields highly dispersed cobalt nanoparticles embedded in a carbon matrix which shows exceptional catalytic activity in the reverse water gas shift reaction. Incorporation of nitrogen into the carbon-based supports resulted in increased reaction activity and selectivity toward carbon monoxide (CO), likely because of the formation of a Mott–Schottky interface. At 300 °C and a high space velocity of 300 000 mL g–1 h–1, the catalyst exhibited a CO2 conversion rate of 122 μmolCO2 g–1 s–1, eight times higher than that of a reference Cu/ZnO/Al2O3 catalyst. Our experimental and computational results suggest that nitrogen-doping lowers the energy barrier for the formation of formate intermediates (CO2* + H* → COOH* + *), in addition to the redox mechanism (CO2* + * → CO* + O*). This enhancement is attributed to the efficient electron transfer at the cobalt–support interface, leading to higher hydrogenation activity and opening new avenues for the development of CO2 conversion technology.