Abstract
•A new CNFs based Cu/ZrO2 catalyst for CO2 hydrogenation to methanol was investigated.•CNFs served well as a catalyst support in slurry reactor for the title reaction.•N2O chemisorption studies revealed that SCu was significantly increased by Nb promotion.•Efficient CO2 conversion at relatively low reaction temperature.•The efficiency of the catalyst was enhanced incorporation Nb content to the catalyst.
A series of carbon nanofibres supported Cu/ZrO2/Nb2O5 catalyst synthesized by deposition precipitation method were extensively investigated in relation to their performance in hydrogenation of CO2 to methanol. In order to study the promotion effect of niobium, catalysts were loaded with 0.4, 0.8 and 1.2wt.% of Nb2O5. Incorporation of Nb2O5 facilitated 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 Nb2O5 to the catalysts. Activity studies of Nb2O5 doped Cu/ZrO2 catalysts were evaluated in a slurry reactor with a CO2/H2 gas mixture of 1:3 volume ratio, 180oC temperature and 3.0MPa total pressure. The highest activity was achieved with the incorporation of 0.8wt.% 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.