In this work, we performed DFT calculations to systematically examine 26 d-block transition metals for AOR considering all possible reaction mechanisms. In addition to GM and NN mechanisms, we investigated electrochemical N-N coupling processes. We employed linear scaling relations and Brønsted-Evans-Polanyi (BEP) relations to construct a two-dimensional kinetic volcano plot through the microkinetic modeling. We found that a contribution of electrochemical N-N coupling is more significant than thermochemical GM/NN mechanisms, highlighting the importance of including electrochemical pathways to rationally predict catalytic activities. The microkinetic modeling results confirmed that Pt is the most active monometallic catalyst and provided a design strategy to improve the catalytic activity. Based on the suggested strategy, we screened bimetallic alloys consisting of two metals with different N-affinities and proposed a few alloy combinations (IrAu3, RhAg3, NiCu3, RhAu3, PtCu3, NiAg3, PdCu3 and NiAu3) as more active catalysts than Pt. We expect this work to provide a fundamental understanding and be a basis of developing new active catalysts for AOR.