The Hydrogen Economy

Abstract

If the fuel cell is to become the modern steam engine, basic research must provide breakthroughs in understanding, materials, and design to make a hydrogen-based energy system a vibrant and competitive force

An electrochemical impedance study of the oxygen evolution reaction at hydrous iron oxide in base

“…This is the duplex layer model proposed by Burke and coworkers 34 and depicted graphically in Fig. 2a 3 ] 3À has been proposed as a formula for the repeating unit of the outer Fe(III) based oxide product with charge neutrality maintained by associated counter-ions. On repetitive cycling, this porous outer layer increases in thickness at the expense of the underlying metal.…”

Redox and electrochemical water splitting catalytic properties of hydrated metal oxide modified electrodes

“…Indeed such DSA type electrodes were central in showing that noble metal oxides show significant enhancements in electrolytic activity over that of the bare metal. 49,51 Subsequently, various non-noble metal oxides and mixed oxides have also received considerable attention, among these materials the most notable include spinels such as NiCo 2 O 4 30-33 and Co 3 O 4 , [34][35][36] along with various perovskites. [39][40][41][42] The oxide materials used in DSA type electrodes are most commonly prepared by the thermal decomposition of precursor metal salts, usually chlorides or nitrates, and therefore typically consist of compact anhydrous oxides such as the rutile, perovskite and spinel materials discussed above, in which oxygen is present only as a bridging species between two metal cations and ideal crystals constitute tightly packed giant molecules.…”

“…Indeed it has been shown that, at a given operational current density, this relatively large anodic oxygen evolution overpotential is the principal factor limiting the efficiency of industrially important cathodic processes such as metal electrowinning and hydrogen production via alkaline water electrolysis. 4,6,7,9,263,264 Consequently, there has been considerable research effort devoted to decreasing oxygen evolution overpotentials, through the development of novel anode materials such as those outlined above, and to the elucidation of possible mechanistic pathways at these electrode surfaces. 10,11,46 In this context, we have adopted a classical electrochemical approach in our examination of the kinetics of the OER at metal oxide and oxidized metal electrodes.…”

“…3 Consequently, the use of hydrogen as a fuel has been proposed as the basis for a long term energy conversion and storage option, the so called hydrogen economy, consisting of the production of molecular hydrogen from nonfossil sources, its distribution and storage, and its cold combustion in a fuel cell to generate electricity. 4 Of course when considering the environmental impact of an energy source, its method of production, and not just the products of its combustion, must also be taken into account. Currently, the dominant industrial method of hydrogen production is from the steam reforming of natural gas.…”

Recent developments of molybdenum and tungsten sulfides as hydrogen evolution catalysts

“…Hydrogen is one promising candidate as the energy carrier. 2 Today, most hydrogen is produced industrially by steam reforming, i.e., the reaction of methane and water to form hydrogen and carbon dioxide. Although there are still enormous amounts of methane on the earth, it is not a renewable energy source and the problem of CO 2 release is not solved, but shifted from the end-user to the production.…”