Synthesis of methanol from CO hydrogenation on surfaces of ZnO(0001), CeO2(111) and ZnO/CeO2(111)

W.G. REIMERS; M.A. BALTANÁS; M. M. BRANDA

Congreso; 10th Congress of the World Association of Theoretical and Computational Chemists; 2014

10th Congress of the World Association of Theoretical and Computational Chemists

The need to give up fossil fuels and find new sources of clean and efficient energy alternatives is pointed out by many authors. Nowadays, Hydrogen is presented as an ideal fuel, but there are even serious difficulties to overcome, specially, the problem of gas storage. Methanol is an alternative fuel, particularly, for vehicles all over the world. There is plenty of reports about methanol synthesis from CO2, CO and H2 [1,2] -[i], following different reaction pathways, such as the hydrogenation of CO, Yang et. al. [3] worked on the methanol synthesis of from CO, CO2 and H2 on catalytic surfaces of Cu and; they have concluded that the carbon source for this synthesis -at low temperatures (<443K), comes mainly from CO.  The aim of this work is the study of the hydrogenation reactions from CO to methanol, on catalytic surfaces of ZnO(0001), CeO2(111) and ZnO(monolayer)/CeO2(111). The reaction energy values of each step up to the complete hydrogenation of CO were calculated by DFT (Density Functional Theory) method, see reactions (1). Then, the energy barriers were also calculated for the first hydrogenation -from CO to formyl, and for the last one -from methoxi to methanol. The latter is proposed as the rate-determining step in the total reaction [4]. On each reaction step, different surface reactivities were found for CeO2(111) and ZnO(0001), however, an important increase in the effective catalytic reactivity is observed when a ZnO monolayer is deposited on Ceria with respect to the pure oxides.  Acknowledgments: The authors acknowledge the financial support of CONICET and FONCyT, argentina.  References:  [1] J.B. Hansen, P.E.H. Nielsen, In Handbook of heterogeneous Catalysis; G. Ertl, H. Knozinger, F. Schüth, J. Weitkamp, Eds; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, (2008). [2] J. Tabataei, B. Sakakini, K. Waught, Catal. Lett. 110 (2006) 77. [3] Y. Yang, C.A. Mins, D.H. Mei, C.H.F. Peden, C.T. Campbell, J. of Catal. 298 (2013) 10. [4] Y.-F. Zhao, R. Rousseau, J. Li, and D. Mei, J. of Phys. Chem. C 116 (2012) 15952.