Temperature-Dependent Stepwise Dissociation of Methanol on Co(0001).

An atomic-level understanding of the elementary steps of catalytic reactions is crucial for a more molecularly driven catalyst design. Herein, we present a comprehensive study of temperature-dependent stepwise decomposition of methanol on a single-crystal Co(0001) surface using a series of surface science techniques and density functional theory calculation. Visualization of surface products was realized by scanning tunneling microscopy. The first step of methanol dissociation is cleavage of the OH bond to the methoxy group and H atom, showing clover-like and honeycomb structures, respectively. Further dissociation to CO through C-H cleavage was ascertained by infrared reflection absorption spectroscopy, and no intermediates, such as CH2O or CHO, were observed. The final product CO molecules showed versatile configurations with different periodicities on the surface under heating or tip-manipulation conditions.