Tailoring the Electron-Enriched Microenvironment of UiO-66 via Thiol Functionalization to Boost Non-Thermal Plasma CO2 Conversion

The synergistic coupling of nonthermal plasma (NTP) with catalysts offers a promising route for converting CO2/H2O into high-value-added chemicals, but its efficiency is hindered by low-activity catalysts and electron quenching by gaseous H2O. Herein, we propose a “surface electron-enriched microenvironment” strategy to construct a UiO-66(SH)2 catalyst to boost NPT CO2 conversion. Under dielectric barrier discharge (DBD) plasma conditions, the UiO-66(SH)2 catalytic system achieves a CO2 conversion rate of 42.19%, which is 1.88 and 38.87 times higher than that of the unmodified UiO-66 system and plasma-only system, respectively. CO was identified as the dominant carbon-containing product with a selectivity of 82.39%, along with CH4 and trace C2–C3 hydrocarbons. Theoretical calculations and experimental results confirm that the thiol groups in UiO-66(SH)2 create an electron-enriched microenvironment, which significantly enhances the adsorption and activation of CO2 while effectively suppressing the electron quenching effect of gaseous H2O on a plasma-induced CO2 dissociation process. Furthermore, thiol functional groups create an electron-rich microenvironment, effectively reducing the free-energy barrier for the formation of the key intermediate *COOH and thereby accelerating CO2 conversion kinetics. This research provides a rational strategy for achieving efficient and highly selective plasma catalytic CO2 conversion through the metal–organic frameworks (MOFs) functionalization.