Mixtures of LaOCl and LaCl3 are promising catalysts for oxidative chlorination of methane to methyl chloride. The influence of metal dopants such as Co, Ni and Ce, which form stable chlorides under anticipated reaction conditions, on physicochemical and catalytic properties was explored. The presence of markedly redox-active dopants such as cobalt and cerium lead to a higher rate of methane conversion. However, the formed methyl chloride is strongly adsorbed and directly oxidized to CO leading to low methyl chloride selectivity. Doping with nickel weakens, in contrast, the interaction with methyl chloride leading to high methyl chloride selectivity.
A. Van der Heijden of NRSC-Utrecht is gratefully acknowledged for performing the in situ Raman measurements and the fruitful discussions. The authors are grateful to X. Hecht for BET measurements and M. Neukamm for SEM and AAS measurements. This work was partially financed by The Dow Chemical Company. Partial financial support and fruitful discussion in the framework of the network of excellence IDECAT-WP5 (NMP3-CT-2005-011730) is also gratefully acknowledged.