Light‐Induced Redox Looping of a Rhodium/Ce_xWO₃ Photocatalyst for Highly Active and Robust Dry Reforming of Methane

Abstract

Dry reforming of methane (DRM) has provided an effective avenue to convert two greenhouse gases, CH 4 and CO 2 , into syngas. Here, we design a DRM photocatalyst Rh/Ce x WO 3 that invokes both photothermal and photoelectric processes, which overcomes the thermodynamic limitation of DRM under conventional conditions. In contrast to plasmonic or UV-response photocatalysts, our photocatalyst produces a superior light-to-chemical energy efficiency (LTCEE) of 4.65 % with a moderate light intensity. We propose that a light-induced metal-to-metal charge transfer plays a crucial role in the DRM reaction, which induces a redox looping between Ce to W species to lower the activation energy. Quantum mechanical studies reveal that a high oxygen mobility of Ce x WO 3 , accompanied with the formation of oxo-bridge species, results in a substantial elimination of deposited C species during the reaction. Our catalyst design strategy could offer a promising energy-efficient industrial process for DRM.

Catalytic Ozonation of Polluter Benzene from −20 to >50 °C with High Conversion Efficiency and Selectivity on Mullite YMn2O5

“…The monodentate carbonate (m-CO 3 2− , 1610 cm −1 ) and HCO 3 − (1520 cm −1 ) show clear changes with different incident treatments (Figure S32 and Table S14). 7,61,62 It is possible that the carbon-containing species of YMO itself (from citric acid and manganese acetate) are oxidized by ROS. Once C 6 H 6 was introduced, C�O (around 1700 cm −1 ) and m-CO 3 2− vibrations increased significantly and then decreased, suggesting that the accumulated ROS could rapidly react with C 6 H 6 .…”

A novel strategy for dramatically improving catalytic performance for light-driven thermocatalytic CO2 reduction with CH4 on Ru/MgO: the CO2 molecular fencing effect promoted by photoactivation

“…This is consistent with the reported works in which coke was formed for light-driven DRM on the catalysts of supported precious metal nanoparticles such as Pt, Ru, Rh, Pd, etc. 21–27,42–44 Surprisingly, the used Ru/MgO catalyst after 50 h of light-driven thermocatalytic evaluation had no detectable Raman peaks of carbon (Fig. 3C).…”

“…have been reported to possess better resistance to coking than non-precious group VIII metal catalysts, but coking is still inevitable. 21–27,42–44 Secondly, so far, high r and η have been achieved only with high solar light intensities (more than 192 kW m −2 ); 18–20,45–47 thus, an expensive solar concentrated system such as solar thermal power generation is necessary. In recent years, scientists have suppressed carbon buildup and improved catalytic activity by preparing multi-component alloy catalysts, catalysts with reactive oxygen species, and ion-doped catalysts; however, carbon buildup is still unavoidable and the light intensity used is high ( e.g.…”

Combined Photoredox Catalysis for Value-Added Conversion of Contaminants at Spatially Separated Dual Active Sites

“…Independent reduction and oxidation reactions are 2 indispensable counterparts in ubiquitous catalytic systems, which proceed simultaneously to use the electrons (e − ) and holes (h + ) generated by catalysts, respectively [ 1 – 4 ]. The adequate enhancement of combined redox capacity is imperative to maximize the utilization efficiency of input energy and achieve optimum catalytic performance.…”