CoZnyB/Nb2CTx(MXene) for cinnamaldehyde hydrogenation to cinnamyl alcohol: Effects of Zn

Amorphous cobalt boride (CoB) catalysts have superior CO selectivity for cinnamaldehyde (CAL) hydrogenation and low activity. This work prepared CoZn_yB/Nb₂CT_x(MXene) catalysts with different Zn ratios (y=0, 0.025, 0.05, 0.075, and 0.1) via a wet reduction method, which were subsequently utilized in the selective hydrogenation of CAL to cinnamyl alcohol (COL). The CoZn_0.05B/Nb₂CT_x catalyst exhibited superior low-temperature activity, with 91.4 % CAL conversion and a 66.3 % COL yield. SEM and XPS analyses further revealed that Zn enhanced the catalytic activity by generating smaller amorphous alloy particles and exposing more Co⁰ active sites. Furthermore, the NH₃-TPD and adsorbed pyridine DRIFTS results showed that Zn modified the surface acidity of the CoZn_yB/Nb₂CT_x catalyst by generating both Lewis acid sites and Brønsted acid sites, which can facilitate the adsorption of CAL. This work demonstrated that Zn can increase the number of exposed active sites and modify the surface acid properties of amorphous CoB catalysts.