Fabrication of PdZn alloy catalysts supported on ZnFe composite oxide for CO2 hydrogenation to methanol

Abstract

The conversion of CO2 to methanol is of great significance for providing a means of CO2 fixation and the development of future fuels. Supported Pd catalysts have been demonstrated to be active for CO2 hydrogenation to methanol and PdZn alloy plays a key role in this reaction. Therefore, using ZnO-enriched support to increase the amount of nanometric PdZn alloy particles on the surface is an effective strategy to develop ideal catalysts. Herein, we fabricated a PdZn alloy catalyst supported on ZnO-enriched ZnFe2O4 spinel for efficient CO2 hydrogenation to methanol. The amount of formed PdZn alloy and catalyst structure influenced by ZnO concentration on ZnFe2O4 were explored to obtain the best Pd-Z1FO catalyst, which achieves a methanol space-time yield (STY) of 593 gkgcat−1h−1 (12 ggPd−1h−1) with CO2 conversion of 14% under reaction conditions of 290 °C, 4.5 MPa and 21600 mLg−1h−1. Furthermore, the amount of exposed PdZn alloy sites were measured by using CO-pulse chemisorption and we find a linearity between methanol production rate and PdZn alloy sites.