Kazuhiro Nagayama

147 Non-halogen redox catalysis toward green processing

Publisher Summary This chapter describes the oxidation of alkylaroma with ruthenium-substituted heteropolyanion. The Ru-heteropolyanion shows high activity for the oxidation of aromatic compounds to carboxylic acid even at 200°C also in the case of oxidation of p-xylene to terephthalic acid, TPA. Because TPA is solid, mother liquid containing catalyst polyanion is easily recycled. The chapter discusses the development of a non-halogen catalyst system focusing on the production of diphenyl carbonate (DPC), a monomer of polycarbonate, and is mostly prepared from toxic phosgene. The Pd/2-hydroxypyridine (2-PyOH)/Cu/Ce catalyst system shows very high activity in the oxidative carbonylation of methanol to the dimethyl carbonate in spite of no additional halide source such as tetraalkylammonium bromide. The chapter presents the preliminary results of the Pd/2-PyOH catalyst system to the oxidative carbonylation of phenol to DPC. The Pd/2-PyOH catalyst system showed as high activity as that of alternative Pd/co-catalyst systems with the addition of NH4Br in a large amount.