Degradation of azo compounds is challenging but exciting to explore from both environmental and fundamental science aspects. Instead of using high H₂-pressure, heterogeneous cobalt catalyzed efficient tandem transformation of azo compounds to the corresponding imines using stochiometric amount of alcohol is reported. Several cobalt-based heterogeneous catalysts were synthesized by varying the cobalt-ligand ratio, where the catalyst with cobalt:phenanthroline=1:6 was found to be the most active. Utilizing this protocol, selective degradation of a library of azo compounds was effectively carried out using various alcohols.The recyclability test revealed the catalyst could be recycled up to 6^th times. In addition, the control experiments and the Hammett studies revealed this transformation was favorable, with the substrates having electron-donating substituents. The KIE study suggested the alcohol dehydrogenation was one of the slow steps. Moreover, the involvement of ordered transition states was demonstrated by the Eyring analysis.