Angewandte Chemie International Edition
A gas-phase approach to form Zn coordination sites on metal–organic frameworks (MOFs) by vapor-phase infiltration (VPI) was developed. Compared to Zn sites synthesized by the solution-phase method, VPI samples revealed approximately 2.8 % internal strain. Faradaic efficiency towards conversion of CO2 to CO was enhanced by up to a factor of four, and the initial potential was positively shifted by 200–300 mV. Using element-specific X-ray absorption spectroscopy, the local coordination environment of the Zn center was determined to have square-pyramidal geometry with four Zn−N bonds in the equatorial plane and one Zn-OH2 bond in the axial plane. The fine-tuned internal strain was further supported by monitoring changes in XRD and UV/Visible absorption spectra across a range of infiltration cycles. The ability to use internal strain to increase catalytic activity of MOFs suggests that applying this strategy will enhance intrinsic catalytic capabilities of a variety of porous materials.
Yang, Fan; Hu, Wenhui; Yang, Chongqing; Patrick, Margaret; Cooksy, Andrew L.; Zhang, Jian; Aguiar, Jeffery A.; Fang, Chengcheng; Zhou, Yinghua; Meng, Ying Shirley; Huang, Jier; and Gu, Jing, "Tuning Internal Strain in Metal–Organic Frameworks via Vapor Phase Infiltration for CO2 Reduction" (2020). Chemistry Faculty Research and Publications. 1030.
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