Hydrogen Evolution Reaction at Composite‐Coated Raney Nickel Electrodes in Aqueous and Aqueous‐Methanolic Solutions

Abstract

The hydrogen evolution reaction was studied at composite‐coated Raney nickel electrodes in aqueous and aqueous methanolic solutions containing 1MKOH at 25°C, using ac impedance and steady‐state polarization techniques. In aqueous solutions, the experimental results were analyzed by the constant‐phase element (CPE) and the porous electrode models, and the resulting parameters were compared. In aqueous methanolic solutions it was found that the experimental data could be well approximated by both the fractal and the porous models. The kinetic parameters obtained in the different media were compared to those obtained on polycrystalline nickel.

An electrochemically functional layer of hydrogenase extract on an electrode of large and tunable specific surface area

“…8, which presents the performance of our best sample as a Tafel plot featuring the best hydrogen evolution electrocatalyst metals from the literature. [53][54][55][56][57][58][59][60] We observe that near h ¼ 0 our system becomes comparable to platinum, in line with the fact that hydrogenases operate at near-zero overpotential. Our system is also signicantly more efficient than nickel below 200 mV overpotential.…”

Hydrogen evolution on porous Ni cathodes modified by spontaneous deposition of Ru or Ir

“…In warm concentrated alkaline solutions, at a current density of 100 mA cm −2 , overpotentials were reported to be as low as 80-100 mV [2,9]. Similar values were reported also in 1 M NaOH [6], but under these conditions much larger values were also measured [7,8,10]. Materials comparable to Raney-Ni were also prepared by sintering Ni particles [16], but they were found to be less active as cathodes than as anodes in alkaline water electrolysis.…”

“…For these reasons, these materials have been extensively investigated [1]. Most attention has been devoted to Raney-Ni, obtained by leaching a non-noble metal (Zn or Al in most cases) from variously prepared alloy or composite precursors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Owing to the multiplicity of the preparation methods, variable overpotentials were reported for hydrogen evolution at Raney-Ni electrodes.…”

The influence of P content on the electrocatalytic properties of Pd-P electroless alloys for HER on aqueous/ethanolic media

“…Since the effective hydrogenation of organic molecules, obviously a much milder process than the established one occurring at high temperatures and pressures, 24,25 requires the use of organic or mixed media, the produced Pd-P alloys are tested and their electrochemical behaviour analysed, using solutions of tetrabutylammonium perchlorate (TBAP) in ethanol and 50 % (v/v) ethanol/water.…”

“…The use of amorphous materials in electrocatalysis has been subject of many reported studies; special attention has been paid to Ni-based alloys 20,21,24,25 being scarce the literature in what concerns Pd-electroless as electrode material for organic substrates hydrogenation.…”