The influence of adsorbed CO diffusion on the first order phase transition point (y2)of CO oxidation based on Langmuir-Hinshelwood mechanism was studied in detail by Monte Carlo simulation. It was found that CO diffus...The influence of adsorbed CO diffusion on the first order phase transition point (y2)of CO oxidation based on Langmuir-Hinshelwood mechanism was studied in detail by Monte Carlo simulation. It was found that CO diffusion increased the value of the first order phase transition point(y2) and when the ratio(k) of diffusion probability of adsorbed CO to adsorption probability of CO is 100, y2 is equal to 0.642. The correlated y2 value is in good agreement with the theoretical result(O.65) obtained by Mai when k approaches to infinity large.展开更多
The CO oxidation reaction on DLA fractal surface has been studied in detail by Monte Carlo method. It was found that (1) when only adsorption and surface reaction were considered the O atoms and CO molecules on surfac...The CO oxidation reaction on DLA fractal surface has been studied in detail by Monte Carlo method. It was found that (1) when only adsorption and surface reaction were considered the O atoms and CO molecules on surface would self-organize after a reation period, which greatly decreased the touching chance among different reactant molecules and consequently decreased the reaction rate. Furthermore, O atoms tended to be adsorbed at the center or the inner area of DLA surface while CO molecules could exist only at the exterior; (2) the clusters of O atoms could be cut off by vacant active sites after the introduction of CO diffusion on surface, which would further give rise to accelerateion of the reacti0n rate; (3) when the reversible adsorption of CO was introduced O atoms and CO molecules could adsorb evenly on the whole DLA surface and then the reaction would be speeded up greatly, which suggested that for a good catalyst the adsorbing strength should be moderate.展开更多
文摘The influence of adsorbed CO diffusion on the first order phase transition point (y2)of CO oxidation based on Langmuir-Hinshelwood mechanism was studied in detail by Monte Carlo simulation. It was found that CO diffusion increased the value of the first order phase transition point(y2) and when the ratio(k) of diffusion probability of adsorbed CO to adsorption probability of CO is 100, y2 is equal to 0.642. The correlated y2 value is in good agreement with the theoretical result(O.65) obtained by Mai when k approaches to infinity large.
文摘The CO oxidation reaction on DLA fractal surface has been studied in detail by Monte Carlo method. It was found that (1) when only adsorption and surface reaction were considered the O atoms and CO molecules on surface would self-organize after a reation period, which greatly decreased the touching chance among different reactant molecules and consequently decreased the reaction rate. Furthermore, O atoms tended to be adsorbed at the center or the inner area of DLA surface while CO molecules could exist only at the exterior; (2) the clusters of O atoms could be cut off by vacant active sites after the introduction of CO diffusion on surface, which would further give rise to accelerateion of the reacti0n rate; (3) when the reversible adsorption of CO was introduced O atoms and CO molecules could adsorb evenly on the whole DLA surface and then the reaction would be speeded up greatly, which suggested that for a good catalyst the adsorbing strength should be moderate.
