Zn-doped carbon nanocage and Zn-doped silicon nanocage (Zn-C52 and Zn-Si52) as catalysts of nitrogen (N2) reduction to ammonia (NH3) conversion

In this work, the capacities of Zn-doped nanocages (Zn-C52 and Zn-Si52) as catalysts for N2 reduction reaction to produce the NH3 are examined. The Zn atoms are catalytic positions of Zn-C52 and Zn-Si52 nanocages to adsorb the N2 molecule. The Zn-*NN → Zn-*NNH step through distal, enzymatic and alternating mechanisms is the potential limiting step for N2 reduction reaction. Finally, the Zn-C52 and Zn-Si52 nanocages as proposed catalysts have acceptable potential for N2 reduction reaction. [Display omitted] •Potential of Zn-C52 and Zn-Si52 for N2 reduction reaction is investigated.•The Zn atom is catalytic site to adsorb the N2 molecule.•The Zn-Si52 has higher capacity than Zn-C52 to adsorb N2 molecule.•The Zn-C52 and Zn-Si52 are proposed as effective catalysts for N2 reduction reaction.•Zn-Si52 has lower overpotential than metal catalysts for N2 reduction reaction. In this work, the capacities of Zn-doped nanocages (Zn-C52 and Zn-Si52) as catalysts for N2 reduction reaction to produce the NH3 are examined. Results shown that the ΔEadoption of Zn-C52 and Zn-Si52 nanocages are acceptable values and Zn is improved the catalytic activity of C52 and Si52 nanocages. The Zn atoms are catalytic positions of Zn-C52 and Zn-Si52 nanocages to adsorb the N2 molecule. The Zn-*NN → Zn-*NNH step through distal, enzymatic and alternating mechanisms is the potential limiting step for N2 reduction reaction. The pathway of N2 reduction reaction by alternating mechanism is as follow: Zn → Zn-*NN → Zn-*NNH → Zn-*NHNH → Zn-*NHNH2 → Zn-*NH2NH2 → Zn-*NH2 + NH3 → Zn*+ NH3. The Zn-Si52 nanocage can reduce the N2 to NH3 with lower potential limiting step than Zn-C52 nanocage. Finally, the Zn-C52 and Zn-Si52 nanocages as proposed catalysts have acceptable potential for N2 reduction reaction.