Ordered mesoporous Cu–Ca–Zr: A superior catalyst for direct synthesis of methyl formate from syngas

Abstract

It is still a big challenge to obtain both highly active and stable Cu-based catalysts for direct synthesis of methyl formate (MF) from syngas. To address the issue, we have designed and synthesized a series of ternary Cu–Ca–Zr catalysts, namely, the ordered mesoporous Cu–Ca–Zr catalyst prepared by one-pot evaporation-induced self-assembly (EISA) method, and the supported CuO/CaO–ZrO2 catalysts by impregnating with copper precursor or by immobilizing copper nanoparticles. In the latter two catalysts, the ordered mesoporous CaO–ZrO2 support was also prepared by the EISA method. The catalysts were characterized by techniques such as ICP, XRD, TEM, N2 isotherm adsorption-desorption, XPS and H2-TPR, and used for direct synthesis of MF. The results indicated that the catalyst prepared by one-pot EISA method, in which the CuO species are highly dispersed in frame of CaO–ZrO2, exhibits much better activity and stability as compared with the other two catalysts with most of CuO located on the outer surface of the CaO–ZrO2 support, because the former has a higher specific surface area, enhanced synergistic effect and stronger interaction between the CaO–ZrO2 support and CuO active constituent.