Synergistic effect of Mo2N and Pt for promoted selective hydrogenation of cinnamaldehyde over Pt–Mo2N/SBA-15

Abstract

The introduction of a suitable co-catalyst is a promising way to improve the catalytic efficiency of Pt catalysts. Herein, SBA-15 modified with well-dispersed Mo₂N nanoparticles (NPs) is synthesized by anchoring phosphomolybdic acid (HPM) on aminated SBA-15 (SBA-15-NH₂) primarily, followed by nitridation treatment under NH₃. After loading of Pt, the Pt–Mo₂N/SBA-15 catalyst with close-contact Pt and Mo₂N NPs can be formed. The intensive interaction of Pt and Mo₂N benefited from the close contact is verified by XRD and XPS tests. As a result, the ternary Pt–Mo₂N/SBA-15 catalysts have shown superior performance to Pt/SBA-15 catalysts for the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol. The TOF over the 1 wt% Pt–Mo₂N/SBA-15 catalyst is close to that over the 3 wt% Pt/SBA-15 catalyst, but its selectivity to cinnamyl alcohol (COL) is 2.5 times that of 3 wt% Pt/SBA-15. The promoted activity of Pt–Mo₂N/SBA-15 is mainly attributed to the synergistic effect of Pt and Mo₂N NPs, which can cause the full development of the catalytic ability of Pt, thus reducing the Pt usage, through increasing the dispersion of Pt NPs and the fraction of Pt⁰ species in the catalyst.