Collect. Czech. Chem. Commun. 1998, 63, 1927-1937

Effect of Heteroatom on Properties of SiO2-Supported Heteropolymolybdates

Alla Spojakinaa, Nina Kostovaa and Květa Jirátováb

a Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
b Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, 165 02 Prague 6, Czech Republic


SiO2-supported trihydrogen phosphododecamolybdate acid H3PMo12O40 (denoted as H3PMo) and tetrahydrogen silicododecamolybdate acid H4SiMo12O40 (denoted as H4SiMo) and their lithium salts have been studied using IR spectroscopy, temperature programmed reduction and measurement of the thiophene conversion. Lacunar anions of H3PMo and, under some conditions, of H4SiMo are formed if lithium is present in the catalyst. Unlike the supported hetero polyacids, lithium combined with the analogues of defect Keggin anions formed during calcination enhances hydrodesulfurization of thiophene.

Keywords: Silica-supported heteropolymolybdates; Hydrodesulfurization of thiophene; IR spectroscopy; Temperature programmed reduction; Phosphomolybdates; Silicomolybdates; Heterogeneous catalysis.