Constructing directional component distribution in a bifunctional catalyst to boost the tandem reaction of syngas conversion

Abstract

Controlling the formation, diffusion, and conversion of bridging intermediate is important for improving the performance of a tandem reaction over a multi-component catalyst. However, it remains highly challenging because the random distribution of catalytic components via conventional mechanical combination usually endows nondirectional diffusion, resulting in an obvious decrease in catalytic performance. Here, we report a recrystallization methodology dealing with the extruded Cr2O3/ZSM-5 bifunctional catalyst to distribute the oxide on zeolite in an oriented manner. It is confirmed that Cr2O3 preferentially locates on the (100) and (101) surfaces of plate-like ZSM-5 and that the (010) surface is highly exposed. Hence, the diffusion of the bridging intermediate and products is modulated in a directional way, boosting the tandem reaction of CO conversion to aromatics. A 2.99 mmol g−1 h−1 formation rate of aromatic rings (on carbon base) at a 49.4% CO conversion is achieved over the recrystallized catalyst, which is the highest performance data yet reported.