Atomic Ni Species Anchored N‐Doped Carbon Hollow Spheres as Nanoreactors for Efficient Electrochemical CO₂ Reduction

Abstract

Electrochemical CO 2 reduction to value-added chemicals is a critical and challenging process for research of sustainable energy. Herein, we synthesize new nickel single atom catalysts embedded in nitrogen doped hollow carbon spheres (NiÀ N/C-x) via thermal treatment of Ni salts and nitrogen doped hollow carbon spheres (N/C-x). The state of Ni species on NiÀ N/C-x can be tuned by the nitrogen species of N/C-x and pyrrolic-N favors the formation of atomic Ni species. Two catalysts, namely, NiÀ N/C-1/4 contains more pyrrolic-N and more amount of atomic Ni species than that on NiÀ N/C-3/2 have been prepared. During all the measurement potential range, NiÀ N/C-1/4 displays a much higher catalytic activity for CO 2 reduction to CO than NiÀ N/C-3/2. Within the potential range of À 0.63 V to À 0.98 V versus reversible hydrogen electrode (RHE), the faradaic efficiencies of CO on NiÀ N/C-1/4 exceed 70 %. Furthermore, NiÀ N/C-1/4 exhibits high selectivity for CO and excellent stability during 4.5 h of CO 2 reduction electrolysis at the potential of À 0.78 V versus RHE.[a] S.

Robust nickel silicate catalysts with high Ni loading for CO2 methanation

“…Figure 2A and 2B show the XRD patterns of NiPS−X catalysts calcined at 500 °C and reduced at 480 °C, respectively. From Figure 2A, we can see that the calcined NiPS−X catalysts have six diffraction peaks (PDF#49‐1859) at 12.0°, 19.5°, 24.4°, 34.1°, 36.7°, 60.5°, which is the characteristic peak of 1 : 1 NiPS (Ni 3 Si 2 O 9 H 4 ) [25–26] . Also, four close diffraction peaks (PDF#22‐0711) at 19.4°, 28.6°, 35.8°, 60.7° were detected, which belong to the characteristic diffraction peaks of 2 : 1 NiPS (Ni 3 Si 4 O 12 H 2 ) [27–28] .…”

Transition metal-based catalysts for the electrochemical CO2reduction: from atoms and molecules to nanostructured materials

“…309 In another study, an increased content of pyrrolic-N centers in N-doped carbon hollow spheres was obtained by modulating the concentration of the melamine precursor, remarkably increasing the density of Ni sites and, in turn, the catalytic CO 2 RR activity. 310 (bidppz = 11,11 0 -bis(dipyrido[3,2-a:2 0 ,3 0 -c]phenazinyl)) 308 or Ni(NH 3 ) 6 I 2 , 311 were also employed as suitable precursors to achieve robust Ni-N-C SACs for selective CO 2 -to-CO reduction. Remarkably, Wu and coworkers recently reported a Ni SAC containing well-defined Ni-N 4 sites synthesized through a topochemical transformation of a Ni-doped g-C 3 N 4 sample with a carbon layer.…”

Efficient CO2 Electroreduction on Ag2S Nanodots Modified CdS Nanorods as Cooperative Catalysts

“…Electrocatalytic carbon dioxide (CO 2 ) reduction operated by renewable electricity is a promising strategy to achieve carbon neutrality and produce carbon‐based fuels and chemicals from C 1 to C 3 products [1–4] . Especially, the reduction process with two‐electron transfer, in which generating CO and formate, is economically viable according to the techno‐economic analysis [5] .…”