Seleno-analogues of pentlandites (Fe_4.5Ni_4.5S_8−YSe_Y, Y = 1–6): tuning bulk Fe/Ni sulphoselenides for hydrogen evolution

Abstract

A series of hitherto unprecedented seleno-pentlandites (Fe4.5Ni4.5S8-YSeY) and their catalytic activity in the hydrogen evolution reaction is presented.

Enhancing the CO2 Electroreduction of Fe/Ni‐Pentlandite Catalysts by S/Se Exchange

“…In accordance to the previously established synthetic boundaries of Se‐containing pentlandites, our investigations focus on the reported seleno‐pentlandites Fe 4.5 Ni 4.5 S 8‐Y Se Y (Y=1–5, Se‐1 , Se‐2 , Se‐3 , Se‐4 , Se‐5 ) with integer equivalents of selenium as well as the selenium‐free pentlandite ( Pn ) for comparative purposes. The respective materials were synthesized by high‐temperature solid‐state synthesis from the respective elemental mixtures according to previously published reports . The characterization of the materials obtained, especially powder‐XRD, single‐crystal XRD, DSC as well as XPS correspond to the results previously reported by our group .…”

“…The respective materials were synthesized by high‐temperature solid‐state synthesis from the respective elemental mixtures according to previously published reports . The characterization of the materials obtained, especially powder‐XRD, single‐crystal XRD, DSC as well as XPS correspond to the results previously reported by our group . The as synthesized rock material was investigated for its CO 2 RR performance in the form of polished pellet electrodes encapsulated in a Teflon housing (0.071 cm −2 ) using a three‐electrode H‐type cell setup in a continuous CO 2 flow operation mode.…”

“…Thus, we herein set out to assess the effect of S/Se exchange on the CO 2 RR activity in Fe 4.5 Ni 4.5 S 8 pentlandite. This project is further motivated by our recent observation that a stepwise S/Se exchange suppresses the HER activity of Pn most likely due to an increase of the interatomic metal distances among other effects . A high selenium content beyond Fe 4.5 Ni 4.5 S 7 Se should thus inhibit hydrogen evolution and favorable CO 2 RR‐properties due to suppression of its main competitor reaction can be expected.…”

Sustainable and rapid preparation of nanosized Fe/Ni-pentlandite particles by mechanochemistry

“…Previous investigations were mainly performed with rod-type electrodes consisting of the pure material without additives. 6,7,18 Applying these materials, prepared from a cheap and sustainable method, in a PEM-electrolyzer now constitutes a vital step towards their potential future commercial applications. For our experiments, we employed an inhouse build electrochemical PEM-cell (Fig.…”

“…Commonly, pentlandites are synthesized by high-temperature (ca. 1000 C) solid-state reactions under exclusion of air in sealed containers; 6,7,17,18 a highly inefficient method, especially in terms of time, energy input and waste production. Alternative approaches include hydro/ solvothermal coprecipitation methods 13,19 usually followed by an additional annealing 9-11 /suldation 14 step with H 2 S 1 or gaseous sulfur.…”