Improved CO selectivity during CO2 hydrogenation by bimetallic copper-cobalt supported SBA-15

Abstract

Co-Cu/SBA-15 systems have been studied for the reverse water gas shift (rWGS) reaction within mild temperature range of 250–650 ºC. CuOx and CoOx species at different weight ratios were deposited from wet impregnation method over SBA-15 support. We have stated that pre-reduction treatment before reaction leads to the complete Co and Cu reduction for Co-Cu/SBA systems. A low copper content on Co/SBA system leads to similar CO₂ conversion than monometallic Co-catalyst. However, competitive Sabatier side reaction appears almost suppressed. So, upon Cu incorporation a significant improvement on CO yield has been attained with respect to Co/SBA catalyst. Thus, a good compromise is attained at 450 ºC using Co5Cu5/SBA catalyst for which a stable CO₂ conversion of 22 % and 97 % CO selectivity has been obtained under lowest H₂:CO₂ ratio.