Abstract Cobalt and molybdenum are valuable metals whose presence in nature is very limited. The consumed catalyst, which abundantly available the petroleum refinery industry, a potential source of those metals. A hydrometallurgical process using acid as leaching agent usually used to extract separate more effectively. This method considered capable yielding recovery higher percentage metal. In...

Palladium-catalyzed acetylene trimerization and the metathesis of olefins catalyzed by molybdenum and its oxides are investigated in ultrahigh vacuum and at high pressures. Benzene is formed on Pd(111) by the reaction between adsorbed acetylene and a surface C4 metallocycle. The resulting benzene evolves in temperature-programmed desorption in two distinct states. The low-temperature state is p...

The structural evolution of Keggin-type heteropolyoxomolybdates (HPOM) during thermal treatment in propene and in propene and oxygen in the temperature range from 300 to 773 K was investigated by in situ X-ray diffraction (XRD) and in situ X-ray absorption spectroscopy (XAS) combined with mass spectrometry. During treatment in propene or hydrogen and at reaction temperatures above 673 K, the in...

A detailed study on visible light photocatalytic degradation of methylene blue (MB) has been investigated in aqueous heterogeneous media containing hexagonal phase molybdenum oxide (h-MoO3) nanocrystals (NCs) which was identified as a new material for visible light driven photocatalysis. A simple and template-free solution based chemical precipitation method was employed to synthesize h-MoO3 NC...

Retro-aldol reactions have been implicated as the limiting steps in catalytic routes to convert biomass-derived hexoses and pentoses into valuable C2, C3, and C4 products such as glycolic acid, lactic acid, 2-hydroxy-3-butenoic acid, 2,4-dihydroxybutanoic acid, and alkyl esters thereof. Due to a lack of efficient retro-aldol catalysts, most previous investigations of catalytic pathways involvin...