Core-Shell Ni/Sio2@Zro2 Catalyst for Highly Selective Co2 Conversion Accompanied by Enhancing Reaction Stability

Abstract

CO2 RWGS reaction was considered to be a promising process for carbon dioxide conversion, however it retained a big challenge owing to methanation and metal sintering. Therefore, highly selective and stable catalyst desperately needed to be devised. Herein, core-shell Ni/SiO2@ZrO2 catalyst was successfully prepared via in situ hydrothermal synthesis method, with ZrO2 as the coating shell. The optimized Ni/SiO2@4ZrO2 catalyst possessed smaller Ni grain size and enhanced metal-support interaction as well as more oxygen vacancies and Ni3+ sites on the calcined catalyst surface. As a result, under the WHSV of 120000 and 150000 mL/g·h, Ni/SiO2@4ZrO2 displayed a considerable hydrogenation activity and significantly higher selectivity to CO, compared with the Ni/SiO2 catalyst as a reference. During stability tests, Ni/SiO2@4ZrO2 also showed a superior catalytic stability with a steady 100% CO selectivity, carried out at 600 °C for 72 hour. This work provided a novel strategy of designing a core-shell catalyst for CO2 RWGS reaction, and was expected to be put into use in other multiphase reaction process.

Keywords: core-shell structure, ZrO2, in-situ hydrothermal synthesis, CO2 RWGS