Fig. 5: In-situ DRIFTS analysis.

In-situ DRIFTS spectra of a reconstructed Ni-Ce(OH)3/CeO2, b Ni-CeO2, and c H2-treated Ni-Ce(OH)3/CeO2 under the flowing of CO2. The catalysts underwent pre-treatment by a flow of 50% H2/Ar for 1 h. After removing excess H2 by an Ar flow, a flow of 50% CO2/Ar was introduced. The DRIFTS signals were collected at 450 °C every 20 s during a period of 15 min. The reconstructed Ni-Ce(OH)3/CeO2 catalysts were obtained by in-situ treatment of the Ni-Ce(OH)3/CeO2 pre-catalysts under reaction conditions at 600 °C for 2 h. The H2-treated Ni-Ce(OH)3/CeO2 catalysts were obtained by in-situ treatment of the Ni-Ce(OH)3/CeO2 pre-catalysts under H2/Ar (5%) atmosphere at 600 °C for 2 h.