Nitrogen-rich metal-organic framework mediated Cu-N-C composite catalysts for the electrochemical reduction of CO_(2)

Cu-based MOFs,i.e.,HKUST-1,etc.,have been pertinently chosen as the pristine materials for CO_(2) ER due to the unique ability of copper for generation hydrocarbon fuel.However,the limited conductivity and stability become the stumbling-block that prevents the development of it.The exploring of MOFsderived M-C materials starts a new chapter for the MOFs precursors,which provides a remarkable electronic connection between carbon matrix and metals/metal oxides.N-doped M-N-C with extensive M-N sites scattering into the carbon matrix are more popular because of their impressive contribution to catalytic activity and specific product selectivity.Nevertheless,Cu-N-C system remained undeveloped up to now.The lack of ideal precursor,the sensitivity of Cu to be oxidized,and the difficulties in the synthesis of small size Cu nanoparticles are thus known as the main barriers to the development of Cu-N-C electrocatalysts.Herein,a nitrogen-rich Cu-BTT MOF is employed for the derivation of N-doped Cu-N-CT composite electrocatalysts by the pyrolyze method.High-temperature pyrolysis product of Cu-N-C1100exhibits the best catalytic activity for productions of CO(-0.6 V vs.RHE,jCO=0.4 mA/cm^(2))and HCOOH(-0.9 V vs.RHE,jHCOOH=1.4 mA/cm^(2)).

Well-dispersed porous Fe–N–C catalyst towards the high-selective and high-efficiency conversion of CO_(2) to CO

In this study,through direct pyrolysis of a nitrogen-rich metal-organic framework of Fe-BTT at different temperatures and followed by acid treatment,we prepared a series of Fe–N–CT(T=800–1000°C)composite catalysts with uniform cubic morphology and homogeneously distributed active sites.Acid leaching leads to the removal of excess Fe NPs and the exposure of more pyridinic N and porphyrin-like Fe–Nx sites and creates a higher specific surface area.Structural and electrochemical performance test results showed that Fe–N–C900catalyst exhibited the highest selectivity for CO product at–1.2 V vs.Ag/AgCl,with 496 m V of overpotential and 86.8%of Faraday efficiency,as well as excellent long-term stability,due to the good inheritance from rich-N Fe–BTT precursor.