Novel heterogeneous catalyst, supported undecamolybdophosphate: synthesis, physico-chemical characterization and solvent-free oxidation of styrene

Abstract

A novel heterogeneous catalyst comprising undecamolybdophosphate and hydrous zirconia was synthesized, characterized by various physicochemical techniques and used as an efficient heterogeneous catalyst for oxidation of styrene using H(2)O(2) as an oxidant. The novelty of the present work lies in obtaining >99% conversion of styrene with >99% selectivity for benzaldehyde under solvent free mild reaction conditions.

Keggin-type lacunary and transition metal substituted polyoxometalates as heterogeneous catalysts: A recent progress

“…We thought to accept the challenge and started working for the same. In 2011, we were successful to isolate PMo 11 and to stabilise it by supporting on to ZrO 2 (54).…”

“…A series of catalysts comprising of active species and supports (ZrO 2 , Al 2 O 3 , zeolite Hβ, MCM-41, and MCM-48) were synthesized. The detailed characterizations of all synthesized supported catalysts can be found in earlier reports (54)(55)(56)(81)(82)(83)(84)(85)(86)(87)(88)(89).…”

“…They also found that both these species are in equilibrium in solution at pH 1-2 (42 of molybdophosphate anions has been investigated with 31 P NMR spectroscopy, Raman spectroscopy and differential pulse polarography by Rob van Veen et al (44) (46)(47)(48)(49)(50)(51)(52)(53) which also suggested that [PMo 11 O 39 ] 7-compound decomposes or equilibrates are at rates too rapid to permit isolation and purification. Our group (54)(55)(56) has also synthesized sodium salts of monolacunary POMs from individual salts following the method described in Fig. 2.…”

Fundamental Aspects of Rare Earth Oxides Affecting Direct NO Decomposition Catalysis

“…In general, the catalytic activity of a heterogeneous catalyst is related to the physicochemical characteristics of the catalyst surface, [13][14][15] and, in most cases, the catalytic activity is significantly affected by the morphology of the catalyst particles at the microscopic level. [16][17][18] Furthermore, we have recently demonstrated that control of the surface basicity of the catalyst is also important in terms of enhancing its NO decomposition activity.…”

Metal Molybdate Catalysts for the Selective Oxidation of Olefins and Alcohols Using Hydrogen Peroxide as Oxidant

“…Recently, more efficient and environment-friendly heterogeneous catalysts have been developed rapidly. A variety of hydrotalcite-like, [18,19] nano metal oxide, [20,21] heteropolyacids, [22,23] supported transition metal complex, [24,25] molecular sieves [26,27] and noble metals [28,29] have been introduced to the oxidation of olefins and alcohols. Inspirited from these literatures, we coupled Co, Ni and Cu with Mo respectively to prepare corresponding metal molybdates (such as cobalt molybdate).…”