Rational Design of Graphene-Supported Single-Atom Catalysts for Electroreduction of Nitrogen

Abstract

Critically, the central metal atoms along with their coordination environment play a significant role in the catalytic performance of single-atom catalysts (SACs). Herein, 12 single Fe, Mo, and Ru atoms supported on defective graphene are theoretically deigned for investigation of their structural and electronic properties and catalytic nitrogen reduction reaction (NRR) performance using first-principles calculations. Our results reveal that graphene with vacancies can be an ideal anchoring site for stabilizing isolated metal atoms owing to the strong metal−support interaction, forming stable TMC x or TMN x active centers (x = 3 or 4). Six SACs are screened as promising NRR catalyst candidates with excellent activity and selectivity during NRR, and RuN 3 is identified as the optimal one with an overpotential of ≥0.10 V via the distal mechanism.

Progress of Experimental and Computational Catalyst Design for Electrochemical Nitrogen Fixation

“…Besides, various TM sites with different coordination modes on graphene have been theoretically predicted to be great catalysts for eNRR, such as FeB 2 N 2 ( U L = −0.65 V), MoSeC 2 ( U L = −0.41 V), MoB 3 O ( U L = −0.34 V), TiN 4 ( U L = −0.69 V) and VN 4 ( U L = −0.87 V), MoC 1 N 2 with defect ( U L = −0.48 V), VN 4 ( U L = −0.71 V), CrB 3 C 1 ( U L = −0.29 V), MoN 3 ( U L = −0.50 V) and CrN 3 ( U L = −0.75 V), RuN 3 ( U L = −0.26 V), MoN 1 C 2 ( U L = −0.40 V), RuN 2 C 2 ( U L = −0.43 V), and MoS 3 ( U L = −0.40 V) …”

MgH2/single-atom heterojunctions: effective hydrogen storage materials with facile dehydrogenation

“…Carbon-based singleatom catalysts (SACs) can further reduce the relative mass, which endows them with unique advantages as dehydrogenation catalysts. SACs have a maximum atom utilization [42][43][44][45][46][47][48] and excellent performance in many catalytic processes, including oxygen reduction, 49,50 oxygen evolution, 51 nitrogen reduction, [52][53][54][55][56][57] CO 2 reduction, [58][59][60] and hydrogen-involving reactions such as organic dehydrogenation/hydrogenation [61][62][63][64][65][66] and the hydrogen evolution reaction. [67][68][69][70][71][72] Since hydrogen storage has a similar hydrogen transfer process, it can be reasonably expected that the introduction of SACs onto MgH 2 may improve its dehydrogenation/hydrogenation performance.…”

Electrocatalytic Reduction of N2 to NH3 Over Defective 1T′‐WX2 (X=S, Se, Te) Monolayers

“…According to previous studies, [24c,26] there exist several possible mechanisms for the electroreduction of N 2 to NH 3 , namely the distal, alternating, enzymatic, and consecutive (consecutive І or consecutive ІІ) pathways, each of which consists of six hydrogenation steps (Scheme 1). For the end‐on adsorbed *N 2 molecules, the reduction follows the distal, alternative, or consecutive І mechanism; For the side‐on adsorbed *N 2 molecules, the enzymatic or consecutive ІІ mechanism is obeyed.…”

“…The step with the maximum uphill Δ G is called the potential‐determining step (PDS) and that Δ G is denoted as Δ G PDS . The limiting potential ( U L =−Δ G PDS / e ) is the best descriptor to quantify the activity of a catalyst for NRR [24c,27] . Overall, a limiting potential of −0.46 V is required to make the whole reaction proceed forward.…”