Modification of supported Pt catalysts by preadsorbed phosphines: Enhanced selectivity in the oxidation of L-sorbose

被引:29
作者
Mallat, T
Bronnimann, C
Baiker, A
机构
[1] Dept. Chem. Eng. and Indust. Chem., ETH-Zentrum, CH-8092, Zürich
关键词
Pt/alumina; Pt/C; modification; phosphine; sorbose; oxidation;
D O I
10.1016/S0926-860X(96)00252-9
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The influence of phosphine and aminophosphine modifiers on the performance of 5 wt.-% Pt/C and Pt/alumina catalysts was studied in the partial oxidation of L-sorbose with molecular oxygen. The molar ratio of modifier to surface Pt atoms (Pt,) was varied between 0.1 and 1.0. In general, higher modifier/Pt-s ratios resulted in higher selectivity to 2-keto-L-gulonic acid and lower reaction rate. The activity and selectivity of Pt strongly depended on the chemical structure of phosphine. Tributhylphosphine in trace amounts (modifier: Pt-s=0.1 mol/mol; modifier: sorbose = 600 ppm) proved to be an outstanding modifier, which improved the selectivity of Pt/C by 28-37% in the whole investigated conversion range. Monitoring the catalyst potential during the reaction revealed that the oxidation state of Pt decreased by promotion, which is an indication that some side reactions leading to catalyst poisoning are suppressed.
引用
收藏
页码:103 / 112
页数:10
相关论文
共 41 条
  • [31] NASAR K, 1995, CHIRAL REACTIONS IN HETEROGENEOUS CATALYSIS, P141
  • [32] THE OXIDATION OF SMALL ORGANIC-MOLECULES - A SURVEY OF RECENT FUEL-CELL RELATED RESEARCH
    PARSONS, R
    VANDERNOOT, T
    [J]. JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1988, 257 (1-2): : 9 - 45
  • [33] A productive synthesis of l-arcorbic acid (C-vitamin)
    Reichstein, T
    Grussner, A
    [J]. HELVETICA CHIMICA ACTA, 1934, 17 : 311 - 328
  • [34] ROPER H, 1990, CARBOHYDRATES ORGANI, P267
  • [35] SANTHANAM KSV, 1990, CHEM ORGANOPHOSPHORU, V1, P103
  • [36] LEAD MODIFIED PLATINUM ON CARBON CATALYSTS FOR THE SELECTIVE OXIDATION OF (2-) HYDROXYCARBONIC ACIDS, AND ESPECIALLY POLYHYDROXYCARBONIC ACIDS TO THEIR 2-KETO DERIVATIVES
    SMITS, PCC
    KUSTER, BFM
    VANDERWIELE, K
    VANDERBAAN, HS
    [J]. APPLIED CATALYSIS, 1987, 33 (01): : 83 - 96
  • [37] SOKOLSKII DV, 1979, HYDROGENATION SOLUTI
  • [38] OXIDATION OF PROPYLENE-GLYCOL AND LACTIC-ACID TO PYRUVIC-ACID IN AQUEOUS PHASE CATALYZED BY LEAD-MODIFIED PALLADIUM-ON-CARBON AND RELATED SYSTEMS
    TSUJINO, T
    OHIGASHI, S
    SUGIYAMA, S
    KAWASHIRO, K
    HAYASHI, H
    [J]. JOURNAL OF MOLECULAR CATALYSIS, 1992, 71 (01): : 25 - 35
  • [39] VANBEKKUM H, 1990, CARBOHYDRATES ORGANI, P289
  • [40] PLATINUM CARBON OXIDATION CATALYSTS .8. SELECTING A METAL FOR LIQUID-PHASE ALCOHOL OXIDATIONS
    VANDAM, HE
    WISSE, LJ
    VANBEKKUM, H
    [J]. APPLIED CATALYSIS, 1990, 61 (01): : 187 - 197