N‐Coordinated Cu–Ni Dual‐Single‐Atom Catalyst for Highly Selective Electrocatalytic Reduction of Nitrate to Ammonia
Yunlong Wang, Haibo Yin, Dong Feng, Xiaoguang Zhao, Yakun Qu, Lixin Wang, Yue Peng, Dingsheng Wang, Wei Fang, Junhua Li
Abstract
Abstract As a traditional method of ammonia (NH 3 ) synthesis, Haber–Bosch method expends a vast amount of energy. An alternative route for NH 3 synthesis is proposed from nitrate (NO 3 − ) via electrocatalysis. However, the structure–activity relationship remains challenging and requires in‐depth research both experimentally and theoretically. Here an N‐coordinated Cu–Ni dual‐single‐atom catalyst anchored in N‐doped carbon (Cu/Ni–NC) is reported, which has competitive activity with a maximal NH 3 Faradaic efficiency of 97.28%. Detailed characterizations demonstrate that the high activity of Cu/Ni–NC mainly comes from the contribution of Cu–Ni dual active sites. That is, (1) the electron transfer (Ni → Cu) reveals the strong electron interaction of Cu–Ni dual‐single‐atom; (2) the strong hybridizations of Cu 3d—and Ni 3d—O 2p orbitals of NO 3 − can accelerate electron transfer from Cu–Ni dual‐site to NO 3 − ; (3) Cu/Ni–NC can effectively decrease the rate‐limiting step barriers, suppress N–N coupling for N 2 O and N 2 formation and hydrogen production.