Supported core-shell catalysts for enhancing ethanol electrooxidation by C1 pathway.

The direct ethanol fuel cell (DEFC) are considered a promising clean energy conversion technology due to their high energy density and low emissions. However, the anodic ethanol oxidation reaction (EOR) follows a dual-pathway mechanism (C1 pathway and C2 pathway) with low efficiency, which limits the performance and industrial application of DEFC. A multi-strategy approach to balance activity, stability, and C1 pathway selectivity in this work was adopted in order to design high-performance core-shell supported palladium (Pd) based catalysts. Au1@Pdx/TiO2-GO and Au1@Pd1.5Sn0.05/TiO2-NGO of core-shell supported catalyst were successfully prepared using the sol-gel method, which show high performance in the EOR. The peak mass current density of the Au1@Pd1.5/TiO2-GO and Au1@Pd1.5Sn0.05/TiO2-NGO catalyst is 4914.8 mA mgPd-1 and 5038.1 mA mgPd-1, which was 6.0 and 6.2 times of the Pd/C(JM) catalyst (816.4 mA mgPd-1), respectively. At the same time, their residual current density after 5000 s of stability testing is 1757.9 mA mgPd-1 and 2160.5 mA mgPd-1, which was 27.3 and 33.5 times of the Pd/C(JM) catalyst (64.5 mA mgPd-1), respectively. The synergistic effect between the core-shell structure and the composite support effectively enhanced the C1 pathway selectivity, regenerative ability, and resistance to CO poisoning of the catalyst in the EOR.