The important role of metals, their oxides and catalytically interactive supports in contemporary investigations related to rational construction of next-generation devices as alternative energy sources and hi-tech electronics is ambitiously presented throughout this book. The topics involve:Carbonaceous and non-typical platinum-based nanostructured electrode materials as promising candidates for anodic reactions in low-temperature fuel cells; Ruthenium oxide as electroactive material, presented through its innovative synthesis routes involving microwave heating and ultrasonic spray pyrolysis, with the focus on its performances as an electrochemical supercapacitor, but also as a part of multicomponent electrode coating in electrocatalysis of chlorine and oxygen evolution; Alkaline water electrolysis as the simplest method for hydrogen production especially when using renewable energy sources, offering the advantage of simplicity and environmentally clean technology with zero emission of greenhouse gases; New frontiers in electroconductive composite materials and biopolymers combined with noble metal nanoparticles that can be used in nanoelectronics and medical nanotechnologies; The possibilities for the operational improvement of an aluminum-air battery presented through alternative modifications of an Al-anode by alloying with magnesium and electromagnetic bulk structure homogenization; The improvements of copper-based materials as well as the research toward sustainable production of copper itself as an important component for further development of electronic devices.