Cu/Zn/Al/Zr catalysts via phase-pure hydrotalcite-like compounds for methanol synthesis from carbon dioxide

Abstract

Cu/Zn/Al/Zr catalysts with Cu2+:Zn2+:Al3+:Zr4+=2:1:x:0.1 (x=0.6–1.5) were prepared from hydrotalcite-like precursors by co-precipitation method and tested for the CO2 hydrogenation to methanol. Both Cu/Zn/Al/Zr hydrotalcite-like and malachite phase were formed at low Al content. However, with the increase of Al content, the yield of hydrotalcite-like phase increased and phase-pure Cu/Zn/Al/Zr hydrotalcite-like compound was obtained for x≥0.9. In addition, both the specific surface area and the dispersion of Cu increased gradually with the increase of Al, while the exposed Cu surface area first increased until Al content was 27.9mol%, then decreased. The results of catalytic test for CO2 hydrogenation revealed that Cu/Zn/Al/Zr catalysts via phase-pure hydrotalcite-like compounds exhibited much better catalytic performance with higher CO2 conversion and CH3OH selectivity compared with the catalyst derived from mixed phase (hydrotalcite-like and malachite). The Cu/Zn/Al/Zr catalysts with Cu2+:Zn2+:Al3+:Zr4+=2:1:1.2:0.1 resulting from phase-pure hydrotalcite-like precursors afforded the substantial stability and the best catalytic performance.