Real time FITR spectroscopic and kinetic studies of Cu surface reduction by using formic acid vapor

In this study, an real time FTIR system was adopted to monitor the reactions between formic acid vapors and the oxidized copper surface at difference temperatures. A cuprous oxide (Cu₂O) surface layer with the thickness of 130nm can be perfectly reduced to metallic Cu by low concentration formic acid vapor at a temperature down to 200°C, and the reduction rate increases with a higher reaction temperature. It is suggested that there exists a critical temperature at about 250°C, above which H₂ may dissociate into H⁺, and combines with OH^- boned on the sample surface to form large amounts of H₂O. A much higher activation energy may support this point.