Applied Catalysis A: General, Vol.533, 59-65, 2017
Oxidative dehydrogenation of lactic acid to pyruvic acid over Pb-Pt bimetallic supported on carbon materials
Various carbon materials, including activated carbon, flake graphite, carbon black and multiwall carbon nanotubes, were adopted as supports for lead-promoted platinum catalysts in the investigation of aqueous-phase oxidative dehydrogenation of lactic acid to produce pyruvic acid. Among them, thenanoscale 3Pb-1Ft/carbon black catalyst showed the highest TOF (769 h(-1)) and yielded 60% pyruvic acid within 20 min under mild conditions. N-2 adsorption, Raman spectroscopy, thermogravimetry, SEM, TEM and XPS were performed to investigate their different structures, graphitization degrees, metal particle sizes and surface oxidation states. Under the current conditions, smaller support particle size is essential for the enhanced lactic acid transformation rate by favoring the diffusion of reactants; less graphitic structure of catalyst is also beneficial by improving metal particle dispersion and facilitating the exposure of metals. (C) 2017 Elsevier B.V. All rights reserved.