CAJ | 학술논문

采用DMol3程序包中的GGA-PW91方法，结合周期平板模型，对CH3O和CO在Pd(111)表面的反应进行了系统研究。计算结果表明，吸附在Pd(111)表面顶位上的CO分子中C原子所带正电荷最多，容易与亲核试剂反应，化学吸附能稍低，有利于在表面上移动发生亲电插入反应；CH3 O在Pd(111)表面fcc穴位吸附稳定， O原子上所带的负电荷较多，易被亲电试剂进攻。过渡态搜索表明， Pd (111)表面顶位上的CO与fcc穴位上CH3 O反应生成CH3 OOC的为放热反应，反应能垒较低，有利于偶联反应的进行。
채용DMol3정서포중적GGA-PW91방법，결합주기평판모형，대CH3O화CO재Pd(111)표면적반응진행료계통연구。계산결과표명，흡부재Pd(111)표면정위상적CO분자중C원자소대정전하최다，용역여친핵시제반응，화학흡부능초저，유리우재표면상이동발생친전삽입반응；CH3 O재Pd(111)표면fcc혈위흡부은정， O원자상소대적부전하교다，역피친전시제진공。과도태수색표명， Pd (111)표면정위상적CO여fcc혈위상CH3 O반응생성CH3 OOC적위방열반응，반응능루교저，유리우우련반응적진행。
The possible reaction mechanisms of CH3O and CO on Pd(111) surface were studied with GGA-PW91 in the DMol3 software package based on density functional theory( DFT) . The relative calculated results indicate that the equilibrium state of CH3 O adsorbed at fcc position is the most stable configuration with more negative charges on O atom, be apt to be attacked by electrophilic reagents. While, CO adsorbed on top site perpendicularly by the interaction between C atom and Pd surface has lower adsorption energy, and its carbon atoms will possess more positive charges, which avail the migration for electrophilic insert reaction. Compared with CO on the bridge and hollow sites, CO adsorbed on the top sites is the optimistical configuration for the coupled reaction yielding CH3 OOC, which may be attributed to the mobility and electrophilcity of CO.