Enhanced catalytic performance of Pd-Ga bimetallic catalysts for 2-ethylanthraquinone hydrogenation

A series of Pd and Pd-Ga bimetallic catalysts were prepared by a co-impregnation method for 2-ethylanthraquinone (EAQ) hydrogenation to produce hydrogen peroxide. Compared with 0.6Pd catalyst, the hydrogenation efficiency of 0.6Pd1.2Ga catalyst (11.9 g L-1) increases by 32.2%, and the stability of 0.6Pd1.2Ga catalyst is also higher than that of 0.6Pd catalyst. The structures of the samples were determined by N-2 adsorption-desorption, ICP, XRD, CO chemisorption, TEM, H-2-TPR, in situ CO-DRIFTS and XPS. The results suggest that incorporation of Ga species improves Pd dispersion and generates a strong interaction between Ga2O3 and Pd interface or between Pd and support. DFT calculation results indicate that the strong adsorption of carbonyl group on Ga2O3/Pd interface facilitates the activation of EAQ and promotes the hydrogenation efficiency.