Spatial decoupling of dehydrogenation and CO oxidation by Ni-Co-Ti hierarchical trimetallic catalyst for electrocatalytic oxidation of methanol

Methanol electro-oxidation reaction (MOR) is the kernel of methanol fuel cell. When the multi-step microscopic transformations process of MOR couples and occurs on the same active site, undoubtedly it reduces the proba-bility of reaction and increases the steric hindrance, resulting in slow reaction kinetics and degradation of cat-alytic performance. In order to decouple the dehydrogenation and CO oxidation in MOR, herein we synthesized the hierarchical catalyst (NiCo/N-TiO2 @NaOH) with bifunctional spatial distribution, which displayed 73 mA cm-2 at the potential of 1.5 V (vs. RHE) and only 20 % degradation of performance after continuously elec-trolysis over 40,000 s. Based on analysis of mass transfer and electron transport in hierarchical structure, combining with in-situ mass spectrometry and theory calculation, the high MOR performance of NiCo/N-TiO2 can be ascribed to the spatial decoupling the MOR reactions including dehydrogenation under synergic effect of Ni/Co and CO oxidation on N-TiO2 film.

Automated summary

In this study, a hierarchical catalyst (NiCo/N-TiO2 @NaOH) with bifunctional spatial distribution was synthesized, which enhanced the performance of methanol electro-oxidation reaction (MOR) by decoupling the dehydrogenation and CO oxidation reactions.