Adsorption mechanisms over ZrO2-modified Cu(111) surface for X (CH3OH, H2O and CO): A DFT plus U Study

The surface adsorption mechanisms of copper-based catalysts for hydrogen production from methanol are investigated by density functional theory (DFT) calculations. In this study, pure and ZrO2- modified copper surfaces are concerned. All the surfaces and adsorbed configurations are optimized via Dmol3 module and analyzed by density of states (DOS), charge transfer and electron density difference. The results show that the O-Cu bond of pure copper surface and the O-Zr bond of ZrO2-modified surface is formed respectively after adsorption of various adsorbates, where strong interactions and electron migration are detected. Compared to pure copper surface, the ZrO2-modified one shows better adsorption capacity and catalytic activity for hydrogen production. The inhibition of carbon monoxide discharge for stable ZrO2-presorbed configurations are confirmed. In addition, the oxygen vacancy is also considered, and the O-defective surface of Ov1 is the most stable configuration, which can be easily formed. This is beneficial to further hydrogen production reactions like MSR. The heterogeneity of catalyst surface that ZrO2 brings great promotes the adsorption capacity, and this provide theoretic basis for future catalyst design.

Automated summary

The surface adsorption mechanisms of copper-based catalysts for hydrogen production from methanol were investigated using DFT calculations. It was found that ZrO2-modified copper surfaces have better catalytic activity and adsorption capacity, inhibiting carbon monoxide discharge and promoting hydrogen production reactions. The study also considered oxygen vacancies and revealed the beneficial effects of oxygen-defective surfaces on reactions like methane steam reforming for hydrogen production.