Low and High Index Faceted Pd Nanocrystals Embedded in Various Oxygen-deficient WOx Nanostructures for Electrocatalytic Oxidation of Alcohol (EOA) and Carbon Monoxide (CO).

This work suggests a modest hydrothermal method applied for the synthesis of oxygen-deficient WOx (x=2.75, 2.83, and 2.94) nanomaterial with various morphology, such as bundled nanorods (NR), nanobelts (NB), and nanosheets (NS), by changing the inorganic additives, such as HCl, NaHSO4, and HNO3. In addition, the WOx supported high and low index faceted Pd nanoparticles (Pd-WO2.75 NB, Pd-WO2.83 NR, and Pd-WO2.94 NS) have been successfully synthesized by the facile sonochemical method to function as the high-electrocatalytic activity of electrocatalysts for alcohol electrooxidation, including ethanol, ethylene glycol, and glycerol. Among the three different electrocatalysts, the versatile high index {520} faceted Pd nanoparticles on WO2.75 NB (Pd-WO2.75 NB) shows the better electrocatalytic performance compared with low index {100} faceted Pd-WO2.83 NR and Pd-WO2.94 NS nanocomposites. This work has identified that the high density of low coordinated surface atom of Pd strongly interacts alcohol, which facilitates of C-C bonds cleavage and may prevent the CO poisoning of nanoparticles. Furthermore, the high concentration of oxygen deficient provided additional benefit for the generation of OH species and boosted the electrocatalytic performance of alcohols as well.