Dual active sites-dependent syngas proportions from aqueous CO2 electroreduction

Self‐Supported Nickel Single Atoms Overwhelming the Concomitant Nickel Nanoparticles Enable Efficient and Selective CO2 Electroreduction

“…[ 10,25,29 ] On the other hand, no measurable CO 2 RR products but H 2 were detected on Ni@C NPs dominant CFM catalyst (marked as Ni@CFM, Figure S8, Supporting Information). Combing with our previous work, [ 14 ] we inferred that the residue Ni@C NPs in Ni@NCNT/CFM (900) would function as HER sites and thus reduce the FE CO of Ni SA sites, as depicted in Figure 2f. To confirm this, we ground Ni@NCNT/CFM (900) in HCl (marked as H‐Ni@NCNT/CFM (900)) to remove Ni@C NPs as much as possible and further examined its FE CO , which surprisingly increased to about 100% from 80%.…”

“…We tried to further fit EXAFS data to determine the local coordination structure of Ni SA. Unfortunately, similar to the previous literatures, [ 12–14 ] the fitting process is limited by the strong peak of Ni‐Ni. Therefore, the accurate local coordination structure in this self‐supported Ni NPs/SAs‐containing catalyst may not be obtained.…”

“…This strategy can improve the loading mass of SAs, [ 10,11 ] and more importantly, provides a simple and scalable way to prepare self‐supported SACs satisfying the structural requirements of gas diffusion electrode (GDE). [ 12–14 ] When directly used in a flow cell or a membrane electrode assembly configuration, such self‐supported SACs not only optimize the mass diffusion and charge transfer, but also avoid the complex drop‐casting preparation of powdery electrodes. In this regard, industrial‐level current density and stability have been realized using self‐supported SACs in electrocatalysis such as oxygen reduction reaction and CO 2 RR.…”

Confining Chainmail‐Bearing Ni Nanoparticles in N‐doped Carbon Nanotubes for Robust and Efficient Electroreduction of CO2

“…Such durability was much better than Ni@NC/NCNT, Ni@NC and NCNT (Figure S7c and d). More importantly, our catalyst surpassed most state‐of‐the‐art CO‐selective catalysts in terms of long‐term durability in CO 2 RR (Figure 4f and Table S7) [16,17,19,26,33–35,37,60,66,67,69,72,76–94] . These unambiguously demonstrated the advantage of the dual chainmail structure in reinforcing the catalyst and boosting the CO 2 RR performance.…”

“…The results here further proved the lower energy barrier and thus higher activity of Ni@NC@NCNT towards CO 2 RR to produce CO. Moreover, the specific value of 118 mV dec −1 revealed that the rate‐determining step for Ni@NC/NCNT was the initial electron transfer process to form CO 2 .− or the concerted electron‐proton process to form * COOH [32,80–82] . To further determine whether a proton participated in the rate‐determining step, the reaction order of CO 2 RR with respect to bicarbonate was investigated.…”