First Principles Study of Photocatalytic Reduction of CO₂ to CH₄ on WS₂-Supported Pt Clusters

Abstract

CO2 conversion into valuable chemicals and fuels is a sustainable route to the concurrent mitigation of the energy crisis and the greenhouse effect. Herein, first principles calculations were employed to study the photocatalytic CO2 reduction over pristine WS2, S-vacancy WS2, and Pt cluster loaded WS2. Our results indicate that the introducing of S-vacancy and loading of Pt clusters can improve the optical absorption in the visible-light region. Furthermore, S-vacancy can lower the barrier (by about 0.17 eV) for *COOH intermediate formation. For Pt/WS2, the strong metal–support interaction is confirmed by high adsorption energy and charge transfer. Importantly, the electron-rich Pt cluster promotes *CO intermediates to facilitate the formation of *CHO intermediates and to further protonate to CH4. This study provides some useful insights into designing the catalysts for the reduction of CO2 and further widens the applications of WS2-based catalytic materials.

WS2 supported PtOx clusters for efficient photocatalytic CO2 reduction: a DFT study

“…Additionally, it should be noted that the adsorption strength for *CO (*HCOOH) on Pt 4 O 6 -WS 2 (Pt 8 O 13 -WS 2 ) is quite smaller than that for *CO on the Pt cluster (Pt/WS 2 ) and the Pt single atom (Pt@WS 2 ) (−2.06 and −2.44 eV, respectively). 49,56 Thus, the Δ G max values for photocatalytic CO 2 reduction of PtO x –WS 2 are also smaller than those of Pt/WS 2 49 and Pt@WS 2 . 56 Consequently, PtO x can tune the adsorption strength of reaction intermediates, thus improving the catalytic activity for CO 2 photoreduction.…”

“…It should be noted that the PtO x –WS 2 systems exhibit a wide absorption band from the ultraviolet region to the visible region, where absorption peaks are observed at 250 nm, 400 nm, and 500 nm for four PtO x –WS 2 . Compared with pristine WS 2 , 49 the absorption coefficient of PtO x –WS 2 has an obvious improvement in light absorption, especially for Pt 7 O 10 -WS 2 and Pt 8 O 13 -WS 2 , which is mainly ascribed to the loading of the PtO x clusters. Note that loading of PtO x clusters induces a significant red-shift, broadening the absorption bands as expected.…”

Ionic Liquid Modified Fe-Porphyrinic Metal–Organic Frameworks as Efficient and Selective Photocatalysts for CO2 Reduction

“…Solar energy is a promising alternative to traditional fossil fuels, with growing concern focused on its utilization to reduce resource extraction and carbon emissions. , Photocatalysis is an appealing technology for directly converting solar energy into chemical energy. , Photocatalytic reduction of CO 2 can be combined with carbon capture and storage technology for conversion into fuels and chemicals such as CO, HCOOH, CH 3 OH, CH 4 , , C 2 H 5 OH, and C 2 H 4 using renewable sunlight as an energy source. To achieve efficient photochemical activation and conversion of CO 2 , it is necessary to develop photocatalysts with high absorption efficiency in the visible range, excellent separation of photogenerated electrons and holes, and the ability to adsorb and activate CO 2 at the interface.…”