Density Functional Theory Study of Water-Gas-Shift Reaction on 3Cu/alpha-Al2O3(0001) Surface

作者：Chiang Hsin Ni; Jiang Jyh Chiang^*

来源：Journal of Physical Chemistry C, 2013, 117(23): 12045-12053.

DOI：10.1021/jp312412b

The water-gas-shift reaction (CO + H2O -%26gt; CO2 + H-2) plays a key role in hydrogen economy. First-principles density functional theory has been used to investigate the mechanism of the water-gas-shift reaction on a model consisting of 3Cu atom cluster on an 3Cu/alpha-Al2O3(0001) surface. Three reaction mechanisms-redox, carboxyl, and formate-have been examined. After zero-point energy correction, our calculations show that the redox mechanism is controlled by l-CO2(a) formation and OH(a) diffusion. The carboxyl mechanism is dominated by the carboxyl formation. The OH(a) is a reactive intermediate and plays an autocatalytic role in catalytic WGS reaction. Specially, the OH(a) formation barrier can be reduced to 0.22 eV from the water dimer dissociation, and the H-2(a) formation barrier is extremely low, 0.65 eV, on the 3Cu/alpha-Al2O3(0001) surface.

• 出版日期2013-6-13