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Excessive use of fossil energy causes global warming and other environmental problems. To reduce the greenhouse effect, two major greenhouse gases-CO₂ and CH₄ as the feedback are used to produce syngas (CO and H₂) by CO₂-CH₄ reforming technique (DRM).

The key to DRM is the choice of catalyst. The catalyst for DRM reaction mainly consists of two parts: the active metal and the support, in which a suitable support plays an important role in promoting the reaction activity and stability. Currently, ZrO₂ is considered as a promising catalyst support due to the presence of oxygen vacancies. However, studies on the effect of oxygen vacancies on the ZrO₂ surface for CO₂ adsorption and activation processes are still lacking.

A research group of Juntian Niu from Taiyuan University of Technology investigated the effect of oxygen vacancies for the adsorption and activation of CO₂ on the surface ZrO₂ by density functional theory (DFT) calculations.

They found that the oxygen vacancies contribute greatly to both the adsorption and activation of CO₂, and the essence lies in oxygen vacancies greatly facilitate the charge transfer from the ZrO₂ surface to the CO₂ molecule. Additionally, it was found that t-ZrO₂ with the presence of oxygen vacancies is most favorable to the adsorption and activation of CO₂ by the comparison of different ZrO₂ crystalline phases.

The new findings elucidated the role of oxygen vacancies in CO₂ adsorption and activation for the preparation of high-performance DRM reaction catalysts using ZrO₂. Meanwhile, it provided guidance for the design of CO₂ high-efficient catalysts at an atomic level.

These findings were published in Frontiers in Energy.