CO2 hydrogenation on Au/TiC, Cu/TiC, and Ni/TiC catalysts: Production of CO, methanol, and methane

•Au, Cu, and Ni particles deposited on TiC(0 0 1) display a very high activity for the hydrogenation of CO2.•Titanium carbide enhances the reactivity of the supported metals by 1–2 orders of magnitude.•A major product is CO produced by the reverse water–gas shift reaction through a HOCO intermediate.•For Au/TiC and Cu/TiC, a substantial amount of methanol is produced and no methane is detected.•Ni/TiC produces a mixture of CO, methanol, and methane.

Small Au, Cu, and Ni particles in contact with TiC(0 0 1) display a very high activity for the catalytic hydrogenation of CO2. The major product over these catalysts is CO which is produced by the reverse water–gas shift reaction (RWGS, CO2 + H2 → CO + H2O). In the cases of Au/TiC(0 0 1) and Cu/TiC(0 0 1), a substantial amount of methanol is also produced, but no methane is detected. Ni/TiC(0 0 1) produces a mixture of CO, methanol, and methane. The highest catalytic activity is found for small two-dimensional particles or clusters of the admetals in close contact with TiC(0 0 1). The catalytic activity of the supported metals can be orders of magnitude higher than those of Au(1 0 0), Cu(1 0 0), or Ni(1 0 0). Density functional calculations point to HOCO as a key intermediate for the generation of CO through the RWGS, with the production of methanol probably involving the hydrogenation of a HCOO intermediate or the CO generated by the RWGS.

Graphical abstractSmall Au, Cu and Ni particles in contact with TiC display a very high catalytic activity for the hydrogenation of CO2 being orders of magnitude more active than bulk Au, Cu or Ni.Figure optionsDownload full-size imageDownload high-quality image (175 K)Download as PowerPoint slide