Construction of Zsm-5 Supported Cuo-Zno-Zro2 Heterogeneous Catalysts for Co2 Hydrogenation to Methanol and Dimethyl Ether (Dme): Effects of Zro2

Abstract

Utilization of CO2 as a carbon source for renewable energy has aroused increasing attentions worldwide, among which the one-pot strategy is especially promising to directly convert CO2 to target products. In the present work, heterogeneous catalysts for CO2 hydrogenation to methanol and dimethyl ether (DME) were developed by loading metal catalyst on zeolite, in which effects of ZrO2 were investigated systematically. The results show that the ZrO2 content can be well controlled. Metal catalysts are successfully loaded on ZSM-5 in the form of CuO-ZnO-ZrO2 nanoparticles, and high surface areas are well retained after adding ZrO2. Further analyses confirm intact structures of metal oxide and zeolite. In following catalytic tests, ZrO2-containing catalysts show considerable stability and activity. At 543 K and 3.0 MPa, the typical 2-Zr-MZ presents a 23.5% of CO2 conversion and 88% of DME selectivity, achieving a remarkably high DME space time yield of 1416.4 g/(kgCu·h) on unit mass of copper. ZrO2 herein helps elevate specific surface areas and reduce CuO crystallite sizes, and ultimately raise the apparent activation energy for CO synthesis to hinder its formation. Accordingly, both selectivity and yield of target product can be improved, promoting efficient and precise conversions of CO2 to DME and MeOH.

Keywords: CuO-ZnO-ZrO2, ZSM-5, CO2, methanol, DME