Biomimetic Nitrogen Fixation Catalyzed by Transition Metal Sulfide Surfaces in an Electrolytic Cell

Abstract

The nitrogen reduction reaction was investigated on the surfaces of 18 different stable transition metal sulfides using density functional theory calculations. YS, ScS, and ZrS were modeled in the rocksalt structure with the (1 0 0) facet; TiS, VS, CrS, NbS, NiS, and FeS in NiAs‐type structure with the (1 1 1) facet; and MnS2, CoS2, IrS2, CuS2, OsS2, FeS2, RuS2, RhS2, and NiS2 in pyrite structure for both the (1 0 0) and (1 1 1) orientations. As the first step towards determination of sulfides that are less prone to hydrogen evolution, the competition between adsorption of NNH and H (for the associative mechanism), and between adsorption of N and H (for the dissociative mechanism) on these surfaces was considered. The catalytic activity through both the associative and dissociative mechanisms was explored and the overpotential required for electrochemical ammonia formation is reported. The scaling relations and volcano plots were constructed with free energy of adsorption of NNH or N on the surface as the descriptor. RuS2 was observed as the most active sulfide that could catalyze nitrogen reduction to ammonia at potentials around −0.3 V through the associative mechanism. NbS, CrS, TiS, and VS are also promising candidates for both the associative and dissociative mechanisms with overpotentials for nitrogen reduction around 0.7–1.1 V.

Are There Any Overlooked Catalysts for Electrochemical NH3 Synthesis—New Insights from Analysis of Thermochemical Data

“…Therefore, our predictions are limited by the scaling relations for pure metals. It is, however, possible to break these scaling relations with other types of materials, such as ceramics of, e.g., metal sulfides (Abghoui et al, 2019). Here RuS 2 was predicted to be at the top of the volcano with around 0.35 V in overpotential.…”

Carbon‐Nanoplated CoS@TiO2 Nanofibrous Membrane: An Interface‐Engineered Heterojunction for High‐Efficiency Electrocatalytic Nitrogen Reduction

“…[34] When an itrogen molecule is adsorbed on the surface of CoS,t he electrons of its 3s g orbital (HOMO) can be donated to the unoccupied d orbital of the latter.Moreover,the d-electrons of CoS can, in turn, donate back to the antibonding 1p g *o rbital (LUMO), which facilitates the breakage of the highly inert NNb onds.A ss uch, CoS,a saNiAs-type, narrow-band gap sulfide,isexpected to be apromising candidate for both associative and dissociative mechanisms. [35] More importantly,c ompared to the other nanostructures,2Dnanosheets are featured by larger surface areas and more active sites.T oa lleviate the tendency of these CoS nanosheets to agglomerate, they are confined on the TiO 2 nanofibrous membrane which is aself-supported matrix free of any binders or substrates.B esides,t he intermate coupling between CoS and TiO 2 enables fast reaction kinetics by facilitating the charge transfer at the heterointerface. Thea mmonia yields of the C@CoS@TiO 2 , CoS@TiO 2 ,a nd TiO 2 nanofibrous membranes are compared in Figure S12.…”

Application of Electrospun Nanofibers for Fabrication of Versatile and Highly Efficient Electrochemical Devices: A Review

“…Alternative designs include rotating electrodes to enhance mass transfer without pumping and porous, i.e., three-dimensional electrodes [ 51 ]. Possible applications include, e.g., electrochemical CO 2 reduction [ 52 , 53 , 54 ], heavy metal removal from wastewater by electrodeposition [ 55 , 56 , 57 ], nitrogen reduction [ 58 ], nitrate removal [ 59 , 60 ] or depolymerization of lignin into renewable aromatic compounds [ 61 ], to name just a few.…”

“…The optimized electrodes were afterwards tested in H 2 and CH 4 fuel gases where they showed good thermal and redox cycling stability [ 211 ]. Besides this type of composite [ 212 , 213 ], other material systems as anodes for solid oxide fuel cells are, e.g., Ni-coated yttria-stabilized zirconia nanofiber mats [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 ...…”