Acidity of Group 5 Metal (V, Nb, Ta)-Substituted Keggin and Wells-Dawson Heteropolyacid (HPA) Catalysts and Their Application to Esterification of Acetic Acid with Ethanol

作者：Park Dong Ryul; Park Sunyoung; Choi Jung Ho; Song In Kyu^*

来源：Catalysis Letters, 2010, 135(3-4): 269-274.

DOI：10.1007/s10562-010-0299-y

• Heteropolyacid
• Keggin
• Wells-Dawson
• Acidity
• Esterification

Acidity of group 5 metal-substituted H(4)PW(11)-M(1)O(40) (M = V, Nb, Ta) Keggin and H(7)P(2)W(17)M(1)O(62) (M = V, Nb, Ta) Wells-Dawson heteropolyacid (HPA) catalysts was measured by NH(3)-TPD experiment. Acidity of H(4)PW(11)M(1)O(40) (M = V, Nb, Ta) and H(7)P(2)W(17)M(1)O(62) (M = V, Nb, Ta) HPA catalysts showed the same trend with respect to polyatom substitution in both series of HPA catalysts. Vapor-phase esterification of acetic acid with ethanol was carried out as a model reaction to correlate the acidity with the acid catalysis of the HPA catalysts. Yield for ethyl acetate (a product formed by acid catalysis of HPA) over H(4)PW(11)M(1)O(40) (M = V, Nb, Ta) and H(7)P(2)W(17)M(1)O(62) (M = V, Nb, Ta) HPA catalysts increased with increasing acidity of the HPA catalysts, regardless of the identity of HPA catalyst. Acidity of H(4)PW(11)M(1)O(40) (M = V, Nb, Ta) and H(7)P(2)W(17)M(1)O(62) (M = V, Nb, Ta) HPA catalysts could be utilized as a probe of acid catalysis for esterification of acetic acid with ethanol.

• 出版日期2010-4