In situ study of the formation and stability of supported Pd2Ga methanol steam reforming catalysts

► Supported Pd2Ga nanoparticles as methanol steam reforming (MSR) catalysts. ► Pd2Ga nanoparticles are stable in O2 regarding bulk structure. ► O2 and CO both decompose the intermetallic surface of Pd2Ga nanoparticles. ► During MSR, the surface is in dynamic equilibrium between formation and decomposition. ► During MSR, residual CO is formed by methanol decomposition on patches of metallic Pd.