Strategies to activate inert nitrogen molecules for efficient ammonia electrosynthesis: current status, challenges, and perspectives

Abstract

Electrocatalytic N2 reduction reaction (NRR) offers an alternative to the traditional Haber–Bosch (H–B) process for the synthesis of ammonia (NH3) and receives a surge of interest recently. However, as the...

Advances in Hybrid Composites for Photocatalytic Applications: A Review

“…The process can be divided into four fundamental steps: (I) light absorption to generate electron-hole pairs; (II) separation of excited charges; (III) transfer of electrons and holes to the surface of photocatalysts; (IV) utilization of charges on the surface for redox reactions [ 39 ]. The holes left in the valence band have high oxidizing power and, reacting with water, generate hydroxyl radicals responsible for pollutant degradation.…”

Atomically Precise Dinuclear Ni2 Active Site-Modified MOF-Derived ZnO@NC Heterojunction toward High-Performance N2 Photofixation

“…Ammonia (NH 3 ) is a principal chemical feedstock in the fertilizer industry and also an essential carbon-free energy carrier. − The current NH 3 production depends mainly on the energy-intensive Haber–Bosch process, which contributes to a huge amount of energy consumption and greenhouse gas emission. The photocatalytic nitrogen reduction reaction (pNRR) offers an alternative to the energy-intensive Haber–Bosch process and has received considerable attention due to its merits of being energy saving and environmentally friendly. − Even so, in the past few years, a breakthrough in photocatalytic N 2 fixation has been rarely realized, as the core catalysts lack effective active sites to bind and cleave nitrogen. − In this regard, it is an essential yet challenging theme to construct green and sustainable photocatalysts with abundant active sites for the development of a reliable pathway toward a highly efficient pNRR.…”

Advances in ambient selective electrohydrogenation of nitrogen to ammonia: strategies to strengthen nitrogen chemisorption

“…19,20 Accordingly, the electrocatalytic NRR process has attracted increasing attention in the past years. 21 Nonetheless, the application of the electrocatalytic NRR process is still hampered by two aspects, including (1) the high triple bond (N^N) energy of N 2 molecules up to 941 kJ mol −1 , demonstrating the critical challenge in nitrogen hydrogenation reduction; (2) competing hydrogen evolution reaction (HER), leading to low Faraday Efficiency (FE). [22][23][24] Hence, there is great signicance in industrial applications to develop electrocatalysts with high selectivity and activity to ensure high yields and FE of ammonia synthesis.…”

“…Briey, the electrocatalytic NRR process usually contains three major elementary steps: (i) chemisorption of N 2 onto the electrocatalyst surface; (ii) N 2 activation and subsequent sequential proton-coupled electron transfer (PCET) steps; and (iii) desorption of NH 3 molecules. 21,25 The chemisorption between the electrocatalyst (adsorbent) and the N 2 molecule (adsorbate) is generally considered the prerequisite step for an efficient NRR process. 26 The enhanced chemisorption process can signicantly polarize N 2 molecules and suppress HER, which is benecial for subsequent activation and PCET steps, holding the key to the whole NRR process.…”