论文部分内容阅读
采用蒙特卡洛方法模拟退火计算了CH_4和CO_2在Ni催化剂表面竞争吸附的等量吸附热和等温吸附线,结果表明,较优的操作参数为:温度范围:1000 K~1150 K,压力:101.33 kPa,CO_2/CH_4:大于1.00。随后通过分子动力学模拟计算了CH_4和CO_2解离过程中产生的自由基在Ni(111)表面的吸附行为,其中CH_3、CH和C倾向于吸附在fcc位点,而H更易于在hcp位发生吸附,CH_2在桥位的吸附最优。同时吸附能的绝对值的顺序是:CH_2>CH_4>CH_3>CH>C>H,吸附能的绝对值越大,相应的吸附构象越稳定。而CO_2和CO倾向于吸附在桥位,O更易于在顶位发生吸附,OH在hop位点的吸附最优。
The simulated annealing of Monte Carlo method was used to calculate the adsorption isotherms and adsorption isotherms of CH_4 and CO_2 on the surface of Ni catalyst. The results show that the optimal operating parameters are: temperature range: 1000 K ~ 1150 K, pressure: 101.33 kPa, CO_2 / CH_4: greater than 1.00. Then the molecular dynamics simulations were performed to calculate the adsorption behavior of free radicals on the Ni (111) surface during the dissociation of CH 4 and CO 2, where CH 3, CH and C tend to adsorb on the fcc site, Adsorption occurred, CH_2 adsorption at the bridge position the best. At the same time, the order of the absolute values of adsorption energy is: CH_2> CH_4> CH_3> CH> C> H. The larger the absolute value of adsorption energy, the more stable the corresponding adsorption conformation. However, CO 2 and CO tend to adsorb at the bridge site, while O is more easily adsorbed at the top site and OH at the hop site.