Activation of tungsten carbide catalysts by use of an oxygen plasma pretreatment

Tungsten carbide (WC) has been considered a promising replacement for precious metal-based catalysts and electrocatalysts; however, synthesis of high-quality WC that is free of surface carbon remains a major challenge. Surface carbon adversely influences the catalytic activity of WC and hinders direct interaction between metal adlayer modifiers and the WC substrate. In this letter, we report the beneficial effects of pretreatments of WC foil by atomic oxygen generated in an oxygen plasma source. We found that the graphitic carbon at the WC surface could be removed controllably by the atomic oxygen without causing oxidation of WC, and this improved performances for electrocatalytic methanol oxidation and hydrogen evolution.