【摘要】 利用同位素跳跃技术和闪脱技术测得了CO和H₂在多晶Ni箔上的净吸附和净脱附速度。发现在Ni箔上吸附CO时,存在吸附促进吸附现象。但当吸附H₂时,则不发生此现象。表面上吸附的CO（a）的脱附被气相H₂（g）稍微加速(V_-^co(N_co,P_H2)>0),H₂的吸附减少了CO（a）吸附量。气相中CO（g）也促进了表面上H（a）的脱附(V^H-(N_H,P_co)>0),但表面上的CO（a）并不促进H（a）的脱附(V_H-(N_H,N_co≈0),这可能由于吸附时CO（g）和H（a）发生了相互作用。更多还原

【Abstract】 Adsorption and desorption of CO and H2 on metals of group Ⅷ have been extensively investigated. In order to analyze the reaction mechanism, it is indispensable to measure the forward and backward reaction rate of an elementary step. But the experimental information concerned is rarely available. An isotope-jump method combined with flash desorption technique had been used to measure both the net adsorption rate and net desorption rate of CO on Pd, Rh, Ru and a unique feature of the adsorption and desorption of CO was revealed during actual adsorption reaction. The net desorption rate of CO was obviously an increasing function of the pressure of the ambient CO molecules. This phenomenon is called "adsorption-assisted desorption".In this paper, the same isotope-jump method combined with flash desorption technique was employed to obtain the net adsorption rate and net desorption rate of CO and H2 on Ni polycrystalline. The phenomenon of adsorption-assisted desorption occurs on Ni for CO, but this phenomenon is not observed for H2 on Ni. During adsorption of CO on Ni, H2(g) in gas phase can slightly accelerate the desorption of CO(a) (VCO(ACO,PH2)>0). Adsorption of H2(g) decreases the amount of adsorbed CO(a). Desorption of adsorbed H(a) is accelerated by CO (g) (VH(NH.PCO) >0), but adsorbed CO(a) does not promote the desorption of adsorbed H(a) (VH(NH ,NCO)≈0). It may be due to the interaction between CO (g) and H(a) during adsorption process.更多还原