Oxy-Anionic Doping: A New Strategy for Improving Selectivity of Ru/CeO₂ with Synergetic Versatility and Thermal Stability for Catalytic Oxidation of Chlorinated Volatile Organic Compounds

Abstract

Understanding the formation and inhibition of more toxic polychlorinated byproducts from the catalytic oxidation elimination of chlorinated volatile organic compounds (Cl-VOCs) and unveiling efficient strategies have been essential and challenging. Here, RuO x supported on CePO4-doped CeO2 nanosheets (Ru/Pi-CeO2) is designed for boosting catalytic oxidation for the removal of dichloromethane (DCM) as a representative Cl-VOC. The promoted acid strength/number and sintering resistance due to the doping of electron-rich and thermally stable CePO4 are observed along with the undescended redox ability and the exposed multi-active sites, which demonstrates a high activity and durability of DCM oxidation (4000 mg/m3 and 15,000 mL/g·h, stable complete-oxidation at 300 °C), exceptional versatility for different Cl-VOCs, alkanes, aromatics, N-containing VOCs, CO and their multicomponent VOCs, and enhanced thermal stability. The suppression of polychlorinated byproducts is determined over Ru/Pi-CeO2 and oxy-anionic S, V, Mo, Nb, or W doping CeO2, thus the oxy-anionic doping strategy is proposed based on the quenching of the electron-rich oxy-anions on chlorine radicals. Moreover, the simple mechanical mixing with these oxy-anionic salts is also workable even for other catalysts such as Co, Sn, Mn, and noble metal-based catalysts. This work offers further insights into the inhibition of polychlorinated byproducts and contributes to the convenient manufacture of monolithic catalysts with superior chlorine-poisoning resistance for the catalytic oxidation of Cl-VOCs.

Crystal Engineering of TiO2 for Enhanced Catalytic Oxidation of 1,2-Dichloroethane on a Pt/TiO2 Catalyst

“…Currently, the most common methods used to address the above-mentioned concerns are introducing a second component or optimizing support types to enhance the redox ability and surface acidity, prompting the removal of chlorine species from the catalysts. 4,5 Support properties significantly affect the CVOC catalytic combustion, including the adsorption of reactant molecules, the removal of chlorine species, 6 the interaction with the loaded noble metal, 7 the electron transfer, and the geometric configuration. 8,9 TiO 2 has been used in the efficient degradation of CVOCs due to its excellent electron transfer ability, thermal stability, and acidic properties.…”

“…Meanwhile, abundant chlorine-containing byproducts are easy to produce. Currently, the most common methods used to address the above-mentioned concerns are introducing a second component or optimizing support types to enhance the redox ability and surface acidity, prompting the removal of chlorine species from the catalysts. , …”

Mechanistic Insight into Catalytic Combustion of Ethyl Acetate on Modified CeO2 Nanobelts: Hydrolysis–Oxidation Process and Shielding Effect of Acetates/Alcoholates

“…Esters as an important group of oxygenated volatile organic compounds (OVOCs) typically induce the photochemical smog and human central nervous system damage. The emission of ester compounds (as the common organic solvents) mainly comes from the manufacturing of paints, package printing, adhesives, plastics, and electronic circuits. , Catalytic combustion (catalytic oxidation) is currently recognized as one of the most promising strategies for OVOC elimination due to its high efficiency, low operating temperature, and less secondary pollution. − Cerium oxide (CeO 2 ) with the excellent redox ability and rapid oxygen storage/release capacity has been well applied in the catalytic oxidation of ester compounds or other VOCs. − Although the related topics about “catalytic combustion of ester compounds on CeO 2 -based catalysts” have been reported before, most studies focused on the increased performance and the design of material itself (such as morphological control, the doping of transition metals, or loading with noble metals) ,,− and lacked the deeper mechanistic understandings into the catalytic reaction itself.…”

Research advances in chlorinated benzene-containing compound oxidation catalyzed by metal oxides: activity-enhanced strategies and reaction-facilitated mechanisms

“…Further, the catalytic oxidation method is voted as a preferable one to remove CBCs for its high activity, low investment, and no secondary pollution through the use of catalysts. Supported precious metals (Pt, Pd, and Ru), 5,6 perovskite-type oxides, 7,8 molecular sieves, 9 and transition metal oxides (V, Mn, Ce, Cu, and Fe-based) [10][11][12][13] are applied for the oxidation of CBCs, where most oxidation products are harmless H 2 O, CO 2 , and HCl, avoiding toxic substances produced under high temperature (400-800 °C). 14 To further realize the research progress of catalysts in this field, Citespace was used to analyze the literature on chlorobenzene catalysis in the past ten years (2013-2023) (search term: chlorobenzene catalytic), and 645 papers were selected.…”

“…Further, the catalytic oxidation method is voted as a preferable one to remove CBCs for its high activity, low investment, and no secondary pollution through the use of catalysts. Supported precious metals (Pt, Pd, and Ru), 5,6 perovskite-type oxides, 7,8 molecular sieves, 9 and transition metal oxides (V, Mn, Ce, Cu, and Fe-based) 10–13 are applied for the oxidation of CBCs, where most oxidation products are harmless H 2 O, CO 2 , and HCl, avoiding toxic substances produced under high temperature (400–800 °C). 14…”