Transition‐Metal Borides (MBenes) as New High‐Efficiency Catalysts for Nitric Oxide Electroreduction to Ammonia by a High‐Throughput Approach

Abstract

Here, the authors performed density functional theory calculations to study the catalytic performance of the nitric oxide reduction reaction (NORR) via a series of transition metal borides (MBenes). This work screened the M2B2 type MBenes from the IVB to V transition metals from the periodic table and systematically probed the catalytic activity and selectivity for the NORR process. It has been reported that Fe2B2, Mn2B2, and Rh2B2 can be high‐performance catalysts for converting NO to NH3 with smaller limiting potentials than other MBenes, and Nb2B2 and Hf2B2 have low limiting potentials of −0.11 V and −0.17 V for the NO production of NH3. The binding energy of ΔG*N can be a good descriptor of catalytic performance and is determined by the volcano plot of the rate‐determining step. The reaction mechanisms for NO reduction to NH3, N2, and N2O have been studied in detail, atomic *N can interact with another *N or one *NO molecule to form N2 and N2O via two successive hydrogenations. In this regard, *NO hydrogenation to *NOH has a lower formation energy than *HNO, and the MBenes have high selectivity for promoting the NORR and suppressing the hydrogen evolution reaction competition process.

Amorphous Boron Carbide on Titanium Dioxide Nanobelt Arrays for High‐Efficiency Electrocatalytic NO Reduction to NH3

“…Selective catalytic reduction (requiring a continuous supply of strong reductants) is the most established post‐combustion method for NO abatement, but it suffers from low sustainability due to high operational costs/potential secondary pollution [12] . Ambient electrochemical NO reduction, powered by renewable electricity, has emerged as an amazingly sustainable route for NO removal with various products being obtained simultaneously [13–25] . Among which NH 3 is an essential commodity for supporting the global population as well as modern industries [26, 27] .…”

“…[12] Ambient electrochemical NO reduction, powered by renewable electricity, has emerged as an amazingly sustainable route for NO removal with various products being obtained simultaneously. [13][14][15][16][17][18][19][20][21][22][23][24][25] Among which NH 3 is an essential commodity for supporting the global population as well as modern industries. [26,27] Importantly, NO shows lower cleavage energy than N 2 , a great benefit to more efficient NH 3 electrosynthesis.…”

MBenes: progress, challenges and future

“…Therefore, our group further explored MBenes with more transition metal layers and two thick Cr-based MBenes, Cr 3 B 4 and Cr 4 B 6 , derived from Cr 3 AlB 4 and Cr 4 AlB 6 , respectively, further enriching the members of MBenes. To date, 24 MBenes with orthorhombic structures have been reported, including eighteen M 2 B 2 (M ¼ Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W), 8,[30][31][32][33][34][35] ve M 3 B 4 (M ¼ V, Cr, Mn, Nb, Ta) 33,[36][37][38][39] and one M 4 B 6 (M ¼ Cr). 36 Although CrMnB 2 and CrFeB 2 were investigated, their stability has not been proved.…”

Efficient nitric oxide electroreduction toward ambient ammonia synthesis catalyzed by a CoP nanoarray

“…These results indicate that NO is more inclined to adsorb on Co atoms. To explore the reaction path of NORR on CoP catalysts, various possibilities and combinations of pathways were considered, and the Gibbs free energy of each reaction intermediate was calculated, 13 with the results shown in Fig. S17 †.…”

“…3,9 Notably, ambient NO reduction by electrocatalysis is being investigated as a sustainable approach for NO hydrogenation to other harmless or valuable nitrogen species, using only water and electrical energy. [10][11][12][13][14][15][16][17][18][19][20][21][22][23] Among these products, NH 3 as a critical chemical for producing fertilizers and a potential carbon-free energy carrier with high energy density is a notable target molecule. 24,25 Although NH 3 can be produced by N 2 electroreduction, [26][27][28][29] it is extremely challenging from both thermodynamic and kinetic points of view since N 2 is chemically inert and poorly dissolves in water.…”