Studies On Catalytic Conversion Of CO And H₂O To Alcohols

Catalytic conversion of CO and PfcO to alcohols (methanol and ethanol) is a new promising route for the utilization of CO in industry process. Not only the hydrogen energy is saved, but also the catalyst is composed of transition element. So that this rout is independent of the noble metal.In the present paper, performance of the solvents and the active composition was studies at first and the PbTiO3 catalyst was found to be the best. Moreover, the effects of alkali metal carbonate promoters and the solvents were investigated at the same time. Experimental results showed that with the increase of the solubility of the alkali carbonate (K2CO3 > Na2CO3 > Li2CO3), the subsequent production of alcohols ranged from 2.0 mg.g-1.h-1 to 23.1 mg.g-1.h-1. The results also suggested that the effect of the solvents on PbTiOs catalyst for catalytic conversion of CO and H2O to alcohols was very sensitive. The catalytic activity was found to increase with the alkalescence of solvents. So the two-step reaction mechanism of direct catalytic conversion of CO and H2O to alcohols is presented that the combination of the carbonate recycle and formate catalytic decomposition results in the final alcohols synthesis.Ultrafine catalyst make it possible for the promotion of catalytic activity of alcohols synthesis from catalytic conversion of CO and H2O. For the first tune, it is reported that the ultrafine TiO2 catalyst prepared by sol-gel method has the stable activity. By means of TG-DTA> IR, XRTK TEM and XPS techniques for the characterization of catalysts, different preparation methods were compared.Moreover, the influence of calcining temperature on the reaction performance of the was also investigated. It was found that the STY of MeOH and EtOH increasedwith the calcining temperature and it reached the maximum 1.82mg.m-2.h-1 as the ratio of rutile to anatase is 9:2, while the corresponding conversion of CO did not be effected remarkably.On this basis, the ultrafine PbTiOs particles was prepared by the same method (sol-gel). The dispersion and the distribution of particles is very well, the average particles size is 31.2nm. It is found that with the addition of the TiO2, the proportion of ethanol increases and the CO conversion decreases at the same time.In the present paper, a new process for the regeneration of catalyst in catalytic conversion of CO and H2O was put forward. For the PbTiO3 catalyst, because of the reduction of catalyst in part and the assembling of K2CO3 on the surface of catalyst, the regeneration process includes two steps: oxidation hi air and washing with water. Experimental results show that the order of the two steps has no effect on the performance of regenerated PbTiO3 catalyst. As for the TiO2, only one washing step is required.