CAJ | 학술논문

采用蒙特卡洛方法模拟退火计算了CH4和CO2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，CO2/CH4：大于1.00。随后通过分子动力学模拟计算了CH4和CO2解离过程中产生的自由基在Ni (111)表面的吸附行为，其中CH3、CH和C倾向于吸附在fcc位点，而H更易于在hcp位发生吸附，CH2在桥位的吸附最优。同时吸附能的绝对值的顺序是：CH2> CH4> CH3> CH > C > H，吸附能的绝对值越大，相应的吸附构象越稳定。而CO2和CO倾向于吸附在桥位，O更易于在顶位发生吸附，OH在hcp位点的吸附最优。
채용몽특잡락방법모의퇴화계산료CH4화CO2재Ni최화제표면경쟁흡부적등량흡부열화등온흡부선，결과표명，교우적조작삼수위：온도범위：1000 K~1150 K，압력：101.33 kPa，CO2/CH4：대우1.00。수후통과분자동역학모의계산료CH4화CO2해리과정중산생적자유기재Ni (111)표면적흡부행위，기중CH3、CH화C경향우흡부재fcc위점，이H경역우재hcp위발생흡부，CH2재교위적흡부최우。동시흡부능적절대치적순서시：CH2> CH4> CH3> CH > C > H，흡부능적절대치월대，상응적흡부구상월은정。이CO2화CO경향우흡부재교위，O경역우재정위발생흡부，OH재hcp위점적흡부최우。
Isosteric heat and sorption isotherm of CH4 and CO2 were calculated by Monte Carlo searches as the temperature is slowly decreased, aiming to understand the influence of operating parameter on the Ni catalyst’s activity and selectivity for dry reforming. An optimal operation condition is proposed at temperature from 1000 K to 1150 K and pressure at 101.33 kPa, and CO2/CH4 ratio should be set and maintained at over 1.00. Then, we applied Molecular Dynamics (MD) calculations in the investigation of the adsorption and of the free radicals involved in CO2 and CH4 dissociation process on the (1 1 1) surface of Ni. Our results indicate that CH3, CH and C prefer to adsorbed at the fcc site and H prefer to adsorbed at the hcp site, whereas CH2 prefer to adsorbed on bridge site. We find that the order of the absolute value of the adsorption energy is: CH2>CH4≥CH3>CH>C>H. Besides, CO2 and CO tend to adsorbed on the bridge site, O is more likely to adsorbed at top site, OH adsorbed at hcp site is more favorable than other sites.