CO Chemisorption on CuNi Composite Substrates

The chemisorption energy of CO on bimetallic catalyst Ni/Cu （Cu/Ni） and disordered binary alloys Ni_xCu_1-x is investigated by using the one-electron chemisorption theory and the complex-energy-plane integration approach. The tight-binding approximation is employed to model the substrates. The Green function method and the average T-matrix approximation are used. The results show that
（1） when the Ni is deposited Cu substrate, the chemisorption is strengthened, conversely, the chemisorption is weakened.
（2） the chemisorption of CO on disordered binary alloy Ni_xCu_1-x is strengthened with the increase of bulk Ni concentration, the Cu segregation to the Ni_xCu_1-x alloy surface can weaken the chemisorption.