4 Optimization methods
From the above progresses, the reported N-doped carbon electrocatalysts
containing Ni NPs, Ni single atoms and both have shown high ECR
activity. Regrettably, the performance of Ni-N-C is difficult to meet
the current practical goal. The catalytic activity and precise guidance
of catalytic mechanisms need to be further developed and investigated.
Therefore, in this section, we list the regulation strategies for
promoting ECR activity and selectivity of Ni-N-C materials and discuss
the relevant mechanisms.