Influence of niobium on carbon nanofibres based Cu/ZrO2catalysts for liquid phase hydrogenation of CO2to methanol

Article abstract of DOI:10.1016/j.cattod.2015.06.019

A series of carbon nanofibres supported Cu/ZrO₂/Nb₂O₅catalyst synthesized by deposition precipitation method were extensively investigated in relation to their performance in hydrogenation of CO₂to methanol. In order to study the promotion effect of niobium, catalysts were loaded with 0.4, 0.8 and 1.2 wt.% of Nb₂O₅. Incorporation of Nb₂O₅facilitated copper reduction by exhibiting a shift of highly reduced copper peak to lower temperature. Likewise, surface enrichment of copper was also enhanced by introduction of Nb₂O₅to the catalysts. Activity studies of Nb₂O₅doped Cu/ZrO₂catalysts were evaluated in a slurry reactor with a CO₂/H₂gas mixture of 1:3 volume ratio, 180^oC temperature and 3.0 MPa total pressure. The highest activity was achieved with the incorporation of 0.8 wt.% of Nb₂O₅, illustrating the high degree of CuO crystallization on the surface of catalyst are beneficial for the generation of copper catalyst with enhanced activities.