Boron-Functionalized Organic Framework as a High-Performance Metal-Free Catalyst for N2 Fixation

• Published in: The Journal of Physical Chemistry Letters Vol. 12; no. 50; pp. 12142 - 12149
• Main Authors: Zhou, Wenyang, Shen, Haoming, Xie, Huanhuan, Shen, Yiheng, Kang, Wei, Wang, Qian, Kawazoe, Yoshiyuki, Jena, Puru
• Format: Journal Article
• Language: English; Japanese
• Published: American Chemical Society 23.12.2021; American Chemical Society (ACS)
• Subjects: 07 v; 1200 k; 2 </ sub; 3 </ sub; 70 ev; ammonia using first; benzoquinone units; Biochemistry; Biological Sciences not elsewhere classified; Biophysics; Biotechnology; catalytic pathways; Chemical Sciences not elsewhere classified; containing triquinoxalinylene; corresponding overpotentials; determining step; dimensional analogue; direct band gap; effectively reduce n; electrocatalytic reduction; enzymatic catalytic mechanisms; fixation inspired; free catalyst; functionalized organic framework; functionalized tqbqcof sheet; n – nh; Physical Insights into Chemistry, Catalysis, and Interfaces; Physiology; principles calculations; reduction catalysts reported; thermally stable; tqbqcof; tqbqcof sheet
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.1c02502

Inspired by the recently synthesized covalent organic framework (COF) containing triquinoxalinylene and benzoquinone units (TQBQ) in the skeleton, we study the stability and properties of its two-dimensional analogue, TQBQCOF, and examine its potential for the synthesis of ammonia using first-principles calculations. We show that the TQBQCOF sheet is mechanically, dynamically, and thermally stable up to 1200 K. It is a semiconductor with a direct band gap of 2.70 eV. We further investigate the electrocatalytic reduction of N2to NH3on the Boron-functionalized TQBQCOF sheet (B/TQBQCOF). The rate-determining step of the catalytic pathways is found to be *N–N → *N–NH for the distal, alternating, and enzymatic catalytic mechanisms, with the corresponding overpotentials of 0.65, 0.65, and 0.07 V, respectively. The value of 0.07 V is the lowest required voltage among all of the N2 reduction catalysts reported so far, showing the potential of B/TQBQCOF as a metal-free catalyst to effectively reduce N2to NH3.