Platinum catalysts on activated carbon supports prepared from mononuclear and polynuclear precursors: Influence of porous structure of the support
Статья (Full article),
Activated Carbon: Classifications, Properties and Applications
Nova Science Publishers, Inc.. Hauppauge NY 11788-3619 United States of America.2011.
555 c. ISBN 9781612096841.
Институт катализа им. Г.К. Борескова СО РАН
A number of catalysts have been prepared by adsorption of platinum precursors on activated carbons of different origin followed by reduction in flowing hydrogen. They were characterized by CO chemisorption, TEM and liquid-phase hydrogenation of cyclohexene. Porous structure of the support and the nature of platinum precursor proved to have a profound influence on the properties of catalysts. The metal dispersion of catalysts prepared from platinum (IV) chloride can be controlled in the range from 10 to 90%. Activity of the catalysts reached a maximum in the range of intermediate metal dispersion, with the limit being dependent on the support used. It has been suggested that a part of the supported metal became inaccessible to the organic substrate due to localization of metal particles in narrow pores of the support. The extent of blocking proved to be higher for highly dispersed Pt particles and on the supports with smaller pores. An alternative route to preparing supported Pt catalysts is the synthesis of polynuclear hydroxochloride complexes from Pt(II) chloride that is followed by their deposition on carbon. The catalysts prepared from polynuclear precursor showed high activity even in the range of high metal dispersion and for microporous carbons. Structure of product of Pt(II) chloride hydrolysis was established by means of NMR 195Pt, 17O.