Novel cryptomelane nanosheets for the superior catalytic combustion of oxygenated volatile organic compounds.

This work offers a novel pathway to prepare cryptomelane manganese oxides nanosheets as an superior catalyst for the catalytic combustion of oxygenated volatile organic compounds. The tunnel cryptomelane manganese oxides nanosheets were prepared from layered birnessite via simultaneously tuning pH and molar ratio (R) of the redox-precipitation between oxalic acid and KMnO. Thus, few-layered cryptomelane nanosheets possessing the most predominantly exposed (211) facet are generated at low pH (5.

"Fishing" of heteropolyacids into carbonaceous seine via coking.

The carbon encapsulated tungstophosphoric acid was synthesized by the controlled coking during gas phase reaction of formaldehyde with isobutene. The as-made material showed unique stability toward leaching in the aqueous phase due to localization of HPA clusters inside the porous coke matrix with high activity in the esterification reaction.

Transesterification of diethyl oxalate with phenol over sol-gel MoO(3)/TiO(2) catalysts.

The transesterification of diethyl oxalate (DEO) with phenol to form diphenyl oxalate (DPO) has been carried out in the liquid phase over very efficient MoO(3)/TiO(2) solid-acid sol-gel catalysts. A selectivity of 100 % with a remarkable maximum yield of 88 % were obtained, which opens the route to downstream phosgene-free processes for the synthesis of polycarbonates. Interpretation of the results of various acidity measurements (NH(3) and pyridine desorption, methanol oxidation as a probe reaction) allowed us to identify the catalytic sites as Lewis acid sites.