Bismuth Single Atoms Resulting from Transformation of Metal–Organic Frameworks and Their Use as Electrocatalysts for CO₂ Reduction

Abstract

The electrocatalytic reduction reaction of CO2 (CO2RR) is a promising strategy to promote the global carbon balance and combat global climate change. Herein, exclusive Bi-N4 sites on porous carbon networks can be achieved through thermal decomposition of a bismuth-based metal–organic framework (Bi-MOF) and dicyan­diamide (DCD) for CO2RR. Interestingly, in situ environmental transmission electron microscopy (ETEM) analysis not only directly shows the reduction from Bi-MOF into Bi nanoparticles (NPs) but also exhibits subsequent atomization of Bi NPs assisted by the NH3 released from the decomposition of DCD. Our catalyst exhibits high intrinsic CO2 reduction activity for CO conversion, with a high Faradaic efficiency (FECO up to 97%) and high turnover frequency of 5535 h–1 at a low overpotential of 0.39 V versus reversible hydrogen electrode. Further experiments and density functional theory results demonstrate that the single-atom Bi-N4 site is the dominating active center simultaneously for CO2 activation and the rapid formation of key intermediate COOH* with a low free energy barrier.

Bismuthene for highly efficient carbon dioxide electroreduction reaction

“…However, previously reported bismuth electrocatalysts for CO2RR usually require large overpotentials or only present low current densities. For example, metal Bi, Bi single atomic 13 , Bi spherical nanoparticles 14,15 , Bi nanobelts 16 , thin films 17 , Bi nanowires 18 , and Bi 2 O 3 nanotubes 11 have been synthesized, but all with very limited CO2RR catalytic performance to HCOO − production. Two-dimensional (2D) multilayered Bi nanosheets with limited CO2RR performance [19][20][21] have also been synthesized recently with state-of-the-art synthesis methodologies, including, but not limited to, sonochemical exfoliation of bulk Bi 22 and in situ topotactic electroreduction of Bi precursors 23 .…”

Controllable Synthesis of Leaf‐Like CuO Nanosheets for Selective CO2 Electroreduction to Ethylene

“…Due to the inert chemical activity of CO 2 molecules, highly efficient catalysts are essential for the efficient CO 2 reduction reaction (CO 2 RR) . The mechanism of CO 2 RR are quite complicated and the products are usually diverse, including C 1 (CO, CH 4 , CH 3 OH, HCOOH), C 2 (C 2 H 4 , C 2 H 6 , C 2 H 5 OH, CH 3 COOH) and C 3+ molecules .…”

Modulating Electronic Structure of Metal-Organic Frameworks by Introducing Atomically Dispersed Ru for Efficient Hydrogen Evolution

“…Currently, single-atom catalysts (SACs) have intrigued new interests in heterogenous electrocatalysis because of their outstanding activity and maximum atom utilization e ciency. [42,43] The impressive catalytic activity of SACs greatly results from the distinctive electronic structure of single metal atoms and the interaction between single metal atoms and supports. [44][45][46][47] So, beyond serving as active sites, incorporating single-atom metals into catalysts can also lead to the local electronic structure modulation of initial catalysts, [48] owning to the electronic interaction between them.…”