Volcano plots along intermetallic hypo-hyper-d-electronic phase diagrams and electrocatalysis for hydrogen electrode reactions

The nature, causes and consequences of the existence of volcano plots along transition series with resulting theoretical conclusions have been extende d on the Brewer hypo-hyper-d-electronic combinations of transition metal in termetallic phases. There has been pointed out that every such phase diagra m behaves as the part of Periodic Table between two initial constituents, a nd thereby features the Gschneidner type volcano plots for the hydrogen ele ctrode reactions (heir), in common with well known electrocatalytic volcano curves of H. Kita and M.H. Miles for the hydrogen evolution reaction (her) upon individual transition metals. Several typical Brewer intermetallic sy stems (Ti-Ni, Zr-Ni, Mo-Ni) were investigated and their comparable hydridic and electrocatalytic properties became revealed from volcanic plots along corresponding phase diagrams. In the light of such conclusions, there has b een pointed out that catalytic volcano plots represent in their essence the main criterion and guidance leading to both optimal and synergetic electro catalytic effects and (electro)catalysts for the heir of broader applicatio n in both industrial. electrolytic and catalytic processes and mobile fuel cells for hydrogen powered cars. As the consequence of the present theory, the paper has been used for the promotion of so called Tiney-Ni, as the cou nterpart of more common Raney-Ni catalyst and its advanced electrocatalytic and hydridic properties were illustrated and pointed out in the light of h ypo-hyper-d-electronic features of composite Braver type intermetallic phas es.