UiO-n-membrane regulate bifunctional catalysts GaZrOx/SAPO-34@UiO-n improving CO2 conversion to light olefins

Abstract

Assembling synergistic-functional nanocatalysts is an effective strategy to achieve highly both active and selective conversion of CO2 into light olefins. Herein, the bifunctional GaZrOx/SAPO-34@UIO-n (n = 66, 66-NH2, 67, 67-NH2, 68, 69) catalyst, UiO-n membrane encapsulating monodispersed SAPO-34 zeolite to get the core-shell SAPO-34@UiO-n (S@Un) and then mixed with GaZrOx, is assembled for CO2 hydrogenation to light olefins. The GaZrOx/SAPO-34 shows C2=-C4= selectivity of only 62.1 %, but the selectivity to C2=-C4= reaches 81.8–85.4 % for the GaZrOx/S@Un. Optimizing UiO-n membrane, the GaZrOx/S@U68 exhibits excellent performance for CO2 conversion into light olefins. The selectivity to C2=-C4= reaches 85.4 % at 19.4 % CO2 conversion and 48.1 % CO selectivity. DOS calculations indicates that GaZrOx can effectively promote CO2 hydrogenation. The results reveal the UiO-n membrane-encapsulating-SAPO-34 synergy-enhancing CO2 conversion to light olefins besides the good catalytic matching of GaZrOx to SAPO-34 in the bifunctional catalyst component.