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

Abstract

The nature, causes and consequences of the existence of volcano plots along transition series with resulting theoretical conclusions have been extended on the Brewer hypo-hyper-d-electronic combinations of transition metal intermetallic phases. There has been pointed out that every such phase diagram behaves as the part of Periodic Table between two initial constituents, and thereby features the Gschneidner type volcano plots for the hydrogen electrode 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 systems (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 been pointed out that catalytic volcano plots represent in their essence the main criterion and guidance leading to both optimal and synergetic electrocatalytic effects and (electro)catalysts for the heir of broader application 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 counterpart of more common Raney-Ni catalyst and its advanced electrocatalytic and hydridic properties were illustrated and pointed out in the light of hypo-hyper-d-electronic features of composite Braver type intermetallic phases.