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本文利用差分红外光谱方法研究了不同预处理条件下,CO在4％Ru/Al_2O_3上的吸附,以及H_2和CO在Ru/Al_2O_3上的共吸附。对CO在Ru上吸附态的红外光谱进行了归属,认为2070cm~(-1)—2060cm~(-1)的中频谱带是孪生CO吸附态的对称伸缩振动和线式CO吸附态的伸缩振动相叠合的谱带。讨论了表面碳(C_S)、表面氧(O_S)、表面氢(H_S)对CO吸附态的影响,认为CO在Ru上发生岐化反应形成的表面碳可使Ru=CO键加强,共吸附H_2可使Ru—CO键削弱。表面氧促使形成缺电子的中心,在此中心上生成CO孪生吸附态。CO的孪生吸附是活化吸附过程。
In this paper, the adsorption of CO on 4% Ru / Al_2O_3 and the co-adsorption of H_2 and CO on Ru / Al_2O_3 under different pretreatment conditions were investigated by using differential infrared spectroscopy. The infrared spectra of the adsorption states of CO on Ru are considered. It is considered that the mid-frequency band of 2070cm -1 -2060cm -1 is the symmetrical stretching vibration of twin CO adsorption state and the stretching vibration of CO adsorption state Overlapping bands. The effects of surface carbon (C_S), surface oxygen (O_S) and surface hydrogen (H_S) on the adsorption states of CO are discussed. It is concluded that the surface carbon formed by the disproportionation reaction of CO on Ru can strengthen the Ru = CO bond and adsorb H_2 Ru-CO bond can be weakened. Surface oxygen promotes the formation of electron-deficient centers at which CO twinning states are generated. Twinning of CO is an activated adsorption process.