Hydrogen electrocatalytic synthesis

T.M. GUr and R.A. Huggins, Electrocatalytic synthesis of methane on stabilized zirconia from molecular hydrogen/carbon dioxide mixtures. Solid St, Ionics 5 563 (1981). 

Electrocatalytic Synthesis, Fig. 3 H2-O2 fuel cell for synthesis of netral hydrogen peroxide solution using heat-treated Co-porphyrin/carbon electrocatalyst... 

The preparative use of nitrile reduction has been primarily for the synthesis of amines [1,2,152-157]. This is done in acidic medium and gives fair to good yields. Electrocatalytic hydrogenation of nitriles is also sometimes efficient [158] in these cases, nickel or palladium black, deposited on the cathode, promotes reduction by electrolyti-cally generated hydrogen atoms. 

Reaction or exchange with stable isotopic tracers and quantitative identification of all products by mass spectrometry provides indications for molecular interactions on the surface. Reactions can be studied at steady state or by following the transient distribution of isotopic products. Langer and co-workers (25,26) presented the first steady-state mechanistic analysis for the electrocatalytic hydrogenation of ethylene on Pt in deuterated electrolytes. Proton abstraction in electroorganic synthesis has also been verified using deuterated solvents (374, 375). On-line mass spectrometry permitted indirect identification of adsorbed radicals in benzene and propylene fuel cell reactions (755,795,194). Isotopic radiotracers provided some notion on adsorption isotherms (376, 377) and surface species on electrocatalysts (208, 378, 379). 

Electrocatalysis at metal electrodes in aqueous (1.2) and non-aqueous ( ) solvents, phthalocyanine ( ) and ruthenium ( ) coated carbon, n-type semiconductors (6.7.8),and photocathodes (9,10) have been explored in an effort to develop effective catalysts for the synthesis of reduced products from carbon dioxide. The electrocatalytic and photocatalytic approaches have high faradaic efficiency of carbon dioxide reduction (1,6). but very low current densities. Hence the rate of product formation is low. Increasing current densities to provide meaningful amounts of product, substantially reduces carbon dioxide reduction in favor of hydrogen evolution. This reduction in current efficiency is a difficult problem to surmount in light of the probable electrostatic repulsion of carbon dioxide, or the aqueous bicarbonate ion, from a negatively charged cathode (11,12). 

Kara Y, Inami N, Itagaki H (2007) Synthesis and characterization of high-surface area tungsten carbides and application to electrocatalytic hydrogen oxidation. Appl Catal A Gen 323 86-93... 

Raoof JB, Azizi N, Ojani R, Ghodrati S, Abrishamkar M, Chekin F (2011) Synthesis of ZSM-5 zeolite electrochemical behavior of carbon paste electrode modified with Ni(II)-zeolite and its application for electrocatalytic oxidation of methanol. Int J Hydrogen Energy 36 13295-13300... 

The dendrimer-mediated synthesis of metal nanoparticles was initiated by the pioneering work of Tomalia [48] and Crooks [49] on synthesizing copper nanoclusters in 1998. In 1999, Crooks and Zhao reported two studies on the synthesis of Pt [50] and Pd [51] nanoparticles with PAMAM Starburst dendrimers. In these two studies, the synthesized Pt and Pd nanoparticles were used in electrocatalytic oxygen reduction and homogeneous hydrogenation reactions, respectively. 

The azadithiolate-bridged diiron compounds that have been developed as stmctural model systems for Fe-only hydrogenase are reviewed in this article. The functionalized diiron complexes which show some ability to generate hydrogen are surveyed, with emphasis on the synthesis and the electrocatalytic properties. The electrocatalytic properties of all complexes investigated by cyclic voltammetry in the presence and absence of acid are described. In addition, the application of electrochemical and IR spectroelectrochemical (SEC) techniques to the elucidation of the details of the electrocatalytic proton reduction is described. The functional mechanistic proposals are discussed from these work. 

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