Highly Selective Catalytic Dechlorination of Dichloromethane to Chloromethane over Al−Ti Mixed Oxide Catalysts

• Published in: ChemCatChem Vol. 12; no. 20; pp. 5098 - 5108
• Main Authors: Yoon, Wongeun, Lee, Seungjun, Noh, Yuseong, Park, Seongmin, Kim, Youngmin, Ju Kim, Hyung, Chae, Ho‐Jeong, Bae Kim, Won
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 20.10.2020
• Subjects: Aluminum; Catalysts; Catalytic activity; chloromethane; Dechlorination; Dichloromethane; Heterogeneous catalysis; Lewis acid; metal-metal interactions; Methyl chloride; Mixed oxides; Sol-gel processes; Titanium
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.202000879

In this paper, a series of Al−Ti mixed oxides with different Al/Ti ratios are prepared by a simple sol‐gel method and they are used as active catalysts for selective dechlorination of dichloromethane to chloromethane. The Al−Ti mixed oxide catalyst with the same molar ratio of Al and Ti shows the highest activity in dechlorination of dichloromethane. The strong and abundant Lewis acid sites in the Al−Ti mixed oxides formed along with Al−O−Ti bondings are responsible for the high catalytic activity toward the selective dechlorination reaction in this work. From a kinetic study, the activation energy of this reaction over the optimum Al−Ti mixed oxide catalyst appears to be 59.4 kJ mol−1 based on Langmuir‐Hinshelwood model. The improved catalytic performance suggests that the Al−Ti mixed oxide could be used as the effective catalyst for the highly selective dechlorination of dichloromethane to chloromethane. Heterogeneous catalysis: The Al−Ti mixed oxide showed higher catalytic activity in novel selective dechlorination to convert dichloromethane into value‐added intermediates. The increased amount and strength of acid sites enhanced by formations of Al−O−Ti bonds in the Al−Ti mixed oxide could lead to the improved turnover frequency of catalyst.