Encapsulating Ir nanoparticles into UiO-66 for photo-thermal catalytic CO2 methanation under ambient pressure. Issue 22 (25th May 2022)

• Record Type: Journal Article
• Authors: Tang, Yunxiang; Yang, Zhengyi; Guo, Chan; Han, Hecheng; Jiang, Yanyan; Wang, Zhou; Liu, Jiurong; Wu, Lili; Wang, Fenglong
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 22(2022)
• Page Start: 12157
• Page End: 12167
• Publication Date: 2022-05-25
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta00933a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : This work successfully encapsulates Ir nanoparticles of ca. 1.5 nm into UiO-66 as highly active catalysts for photo-thermal catalytic CO2 methanation under mild conditions. Abstract : Photo-thermal catalysis provides a promising strategy for the efficient conversion of carbon dioxide (CO2 ) into value-added chemicals under mild conditions. Here, we successfully encapsulate iridium (Ir) nanoparticles of ca .1.5 nm into UiO-66, forming Ir@UiO-66 hybrids, as highly active catalysts for CO2 methanation under light irradiation. X-ray photoelectron spectroscopy (XPS) revealed that the electrons are transferred from UiO-66 to Ir nanoparticles, indicating a strong interaction between Ir nanoparticles and the UiO-66 host. Photoelectrochemical measurements indicated that the Ir nanoparticles could effectively facilitate the separation and transfer of photo-induced charge carriers in excited UiO-66, thus promoting H2 cleavage and CO2 activation. As a result, Ir@UiO-66-2 showed an excellent methane (CH4 ) production rate of 19.9 mmol gcat −1 h −1 and high selectivity (∼95%) at 250 °C under light irradiation, far surpassing that in the dark. The in situ diffuse reflectance infrared Fourier transform spectroscopy ( In situ DRIFTS) results revealed that formate (*HCOO) is the key intermediate in the CO2 methanation process, and light irradiation did not alter the reaction pathways while facilitating the conversion of *HCOO species, thus enhancing CH4 production. This study provides new strategies for the future design of catalysts for CO2 methanation under mild conditions.