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As electrocatalysts, molecular catalysts with large aromatic systems (such as terpyridine, porphyrin, or phthalocyanine) have been widely applied in the CO2reduction reaction (CO2RR). However, these monomeric catalysts tend to aggregate due to strong π–π interactions, resulting in limited accessibility of the active site. In light of these challenges, we present a novel strategy of active site isolation for enhancing the CO2RR. Six Ru(Tpy)2were integrated into the skeleton of a metallo-organic supramolecule by stepwise self-assembly in order to form a rhombus-fused six-pointed star R1with active site isolation. The turnover frequency (TOF) of R1was as high as 10.73 s–1at −0.6 V versus reversible hydrogen electrode (vs RHE), which is the best reported value so far at the same potential to our knowledge. Furthermore, by increasing the connector density on R1’s skeleton, a more stable triangle-fused six-pointed star T1was successfully synthesized. T1exhibits exceptional stability up to 126 h at −0.4 V vs RHE and excellent TOF values of CO. The strategy of active site isolation and connector density increment significantly enhanced the catalytic activity by increasing the exposure of the active site. This work provides a starting point for the design of molecular catalysts and facilitates the development of a new generation of catalysts with a high catalytic performance.

The low O2activation ability at low temperatures and SO2poisoning are challenges for metal oxide catalysts in the application of Hg0removal in flue gas. A novel high-entropy fluorite oxide (MgAlMnCo)CeO2(Co-HEO) with the second phase of spinel is synthesized by the microwave hydrothermal method for the first time. A high efficiency of Hg0removal (close to 100%) is achieved by Co-HEO catalytic oxidation at temperatures as low as 100 °C and in the atmosphere of 145 μg m–3Hg0at a high GHSV (gas hourly space velocity) of 95,000 h–1. According to O2-TPD and in situ FT-IR, this extremely superior catalytic oxidation performance at low temperatures originates from the activation ability of Co-HEO to transform O2into superoxide and peroxide, which is promoted by point defects induced from the spinel/fluorite heterointerfaces. Meanwhile, SO2resistance of Co-HEO for Hg0removal is also improved up to 2000 ppm due to the high-entropy-stabilized structure, construction of heterointerfaces, and synergistic effect of the multicomponents for inhibiting the oxidation of SO2to surface sulfate. The design strategy of the dual-phase high-entropy material launches a new route for metal oxides in the application of catalytic oxidation and SO2resistance.

CF4is a strong greenhouse gas with a global warming potential of up to 6500, and its treatment by decomposition at the flue gas temperature range is hindered by the strong C–F bond. This work achieved, for the first time, the decomposition of CF4at the flue gas temperature range via nonthermal plasma coupled with an aluminum/carbon catalyst with a typical decomposition efficiency of 78% for CF4with a concentration of 10%. CF4excited by the plasma will form many excited particles, which react with Al2O3/carbon. The CF4-derived fluorine can react with Al to form AlF3, and meanwhile, the carbon element bonds with oxygen in Al2O3generating CO and/or CO2. The strong acid sites on the catalyst surface are the main factor in promoting CF4decomposition. The decomposition method developed in this work provides a new approach for decomposing perfluorocarbons at low temperatures.