Highly Selective CO₂ Electroreduction to CH₄ by In Situ Generated Cu₂O Single‐Type Sites on a Conductive MOF: Stabilizing Key Intermediates with Hydrogen Bonding

Abstract

It is still a great challenge to achieve high selectivity of CH4 in CO2 electroreduction reactions (CO2RR) because of the similar reduction potentials of possible products and the sluggish kinetics for CO2 activation. Stabilizing key reaction intermediates by single type of active sites supported on porous conductive material is crucial to achieve high selectivity for single product such as CH4. Here, Cu2O(111) quantum dots with an average size of 3.5 nm are in situ synthesized on a porous conductive copper‐based metal–organic framework (CuHHTP), exhibiting high selectivity of 73 % towards CH4 with partial current density of 10.8 mA cm−2 at −1.4 V vs. RHE (reversible hydrogen electrode) in CO2RR. Operando infrared spectroscopy and DFT calculations reveal that the key intermediates (such as *CH2O and *OCH3) involved in the pathway of CH4 formation are stabilized by the single active Cu2O(111) and hydrogen bonding, thus generating CH4 instead of CO.

Conductive phthalocyanine-based metal-organic framework as a highly efficient electrocatalyst for carbon dioxide reduction reaction

“…Recent progress in successful synthesis of electrically conductive two-dimensional (2D) MOFs [26][27][28] has endowed them with highly efficient electrocatlytic performance in CO 2 RR. Nevertheless, to the best of our knowledge, few conductive MOFs have been reported for the electrocatalytic CO 2 reduction and their activities still need to be improved [27,29,30].…”

Conductive Two‐Dimensional Phthalocyanine‐based Metal–Organic Framework Nanosheets for Efficient Electroreduction of CO2

“…Loading electroactive metal complexes into porous conductive substrates is apromising approach to reduce CO 2 with high current density because of their fast electron transfer capacity and accessible active sites.C ompared with other substrates,crystalline porous metal-organic frameworks (MOFs) with designable metal clusters and functional organic linkers have shown high selectivity in electrocatalytic CO 2 RR and other electrocatalytic reaction due to their single active sites and large CO 2 adsorption uptake. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] However,the poor electrical conductivity feature of the traditionally insulating MOFs usually results in low current density in CO 2 RR. Hence,d eveloping conductive MOFs (CMOFs) with highly single-active sites for the CO 2 RR is extremely desirable.…”

Steric Hindrance‐ and Work Function‐Promoted High Performance for Electrochemical CO Methanation on Antisite Defects of MoS2 and WS2

“…[3] CH 4 is a promising C 1 product for CORR, since its energy density is 55.5 MJ kg À 1 , over two times of that of CH 3 OH (22.7 MJ kg À 1 ). [4] To date, substantial effort has been dedicated to exploring excellent electrocatalysts for CO or CO 2 methanation, such as Cu 2 O quantum dots on metal-organic framework, [5] single Zn atoms supported on microporous N-doped carbon, [6] MoP nanoparticles, [7] and bimetallic NiÀ Co nanoparticles. [8] However, there still exist many unresolved issues, such as low concentration of active sites, poor selectivity, and low activity.…”