CO Dissociation on model Co/SiO2 catalysts - effect of adsorbed hydrogen

We found experimental evidence that shows the effect that adsorbed hydrogen can have on CO dissociation. For cobalt nanoparticles supported on SiO2, adsorbed hydrogen enhances CO dissociation. In contrast, adsorbed hydrogen inhibits CO dissociation on a cobalt film supported on SiO2. Considering the nature of cobalt deposited by physical vapor deposition, these results can be explained by a preference for CO dissociation to follow the hydrogen-assisted dissociation mechanism on FCC cobalt and step-edges, while the direct dissociation mechanism is preferred on HCP cobalt. These results are in agreement with previous theoretical results.

Automated summary

Experimental evidence shows that adsorbed hydrogen has different effects on CO dissociation for cobalt nanoparticles supported on SiO2 versus cobalt film supported on SiO2. The preference for CO dissociation to follow hydrogen-assisted dissociation mechanism on FCC cobalt and step-edges, while direct dissociation mechanism is preferred on HCP cobalt, can be explained by the nature of cobalt deposited by physical vapor deposition. These results are consistent with previous theoretical findings.