TY - JOUR
T1 - Silica-supported chromia-titania catalysts for selective formation of lactic acid from a triose in water
AU - Takagaki, Atsushi
AU - Goto, Hiroshi
AU - Kikuchi, Ryuji
AU - Oyama, S. Ted
N1 - Funding Information:
The authors thank Dr. Takayuki Iida for the UV–vis measurement. This work was supported by JSPS KAKENHI Grant Number JP 25709077 .
PY - 2019/1/25
Y1 - 2019/1/25
N2 - A variety of silica-supported metal oxide catalysts were prepared by the incipient wetness impregnation method and were used for the conversion of dihydroxyacetone to lactic acid. A titanium oxide catalyst with Brønsted acid sites was selective to an intermediate, pyruvaldehyde and a chromium oxide catalyst with Lewis acid sites was selective to lactic acid. The co-impregnation of chromium- and titanium oxides with different ratios accelerated the reaction rate and improved the lactic acid yield up to 80% at 130 °C. Pyridine-adsorbed Fourier-transform infrared spectroscopy indicated that the silica-supported mixed oxides had both Brønsted acid and Lewis acid sites and the trend of the Lewis/Brønsted ratio was close to that of selectivity to lactic acid. Diffuse reflectance UV–vis spectroscopy showed that the silica-supported chromia-titania catalyst composed of isolated Cr and Ti species in tetrahedral coordination. Kinetic analysis revealed that the two critical rate constants, pyruvaldehyde formation and lactic acid formation, for the chromia-titania catalyst were much higher than those of the titania and chromia catalysts.
AB - A variety of silica-supported metal oxide catalysts were prepared by the incipient wetness impregnation method and were used for the conversion of dihydroxyacetone to lactic acid. A titanium oxide catalyst with Brønsted acid sites was selective to an intermediate, pyruvaldehyde and a chromium oxide catalyst with Lewis acid sites was selective to lactic acid. The co-impregnation of chromium- and titanium oxides with different ratios accelerated the reaction rate and improved the lactic acid yield up to 80% at 130 °C. Pyridine-adsorbed Fourier-transform infrared spectroscopy indicated that the silica-supported mixed oxides had both Brønsted acid and Lewis acid sites and the trend of the Lewis/Brønsted ratio was close to that of selectivity to lactic acid. Diffuse reflectance UV–vis spectroscopy showed that the silica-supported chromia-titania catalyst composed of isolated Cr and Ti species in tetrahedral coordination. Kinetic analysis revealed that the two critical rate constants, pyruvaldehyde formation and lactic acid formation, for the chromia-titania catalyst were much higher than those of the titania and chromia catalysts.
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U2 - 10.1016/j.apcata.2018.11.018
DO - 10.1016/j.apcata.2018.11.018
M3 - Article
AN - SCOPUS:85057260050
SN - 0926-860X
VL - 570
SP - 200
EP - 208
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -