Methanol synthesis and oxidation reactions

13 Monometallic nanocatalyst systems copper nanocatalysts supported on silica (Cu/Si02) 

The mechanism for methanol synthesis from mixtures of H2, CO and CO2 over supported Cu catalysts have been studied extensively in the literature using a number of chemical methods (Bell et al 1995). One of the key issues has been the role of CO and CO2 in maintaining the carbon supply for methanol synthesis or interconversion betwen the two via the water-gas shift reaction  

Unpromoted Cu/Si02 is found to have a low activity for methanol synthesis from H2/CO mixtures, whereas an increased activity from H2/CO2. Alkali metal promotion increases the activity for methanol synthesis from the H2/CO mixtures, probably due to the increase in surface OH groups engaged in the formation of the formate species which are the precursors to the methanol. Cu/Si02 powder catalysts (with 5 wt% Cu) can be prepared by ion exchange of silica with Cu(NOs)2 in aqueous solution, followed by calcination and reduction. Such preparations contain very fine Cu particles ( 0.5 nm) on a powdered silica support as revealed by HRTEM. 

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