Complexing‐Coprecipitation Method to Synthesize Catalysts of Cobalt, Nitrogen‐Doped Carbon, and CeO₂ Nanosheets for Highly Efficient Oxygen Reduction

Abstract

The oxygen reduction reaction (ORR) is the key cathode reaction in renewable‐energy technologies. Developing highly efficient, low‐cost, methanol‐tolerant and durable ORR catalysts is highly needed. In this research, we reported a simple complexing‐coprecipitation method to synthesize CeO2 nanosheets encapsulated by a nitrogen‐doped carbon (NC) layer with uniformly dispersed Co nanoparticles catalysts on the surface. In particular, the 0.5Co‐NC‐CeO2 sample exhibits high ORR catalytic activity with an onset potential of 875 mV (vs. RHE), a diffusion‐limited current density of 4.72 mA/cm2 and a positive half‐wave potential of 817 mV (vs RHE), while 20% Pt/C presents an onset potential of 934 mV (vs. RHE), a diffusion limited current density of 5.8 mA/cm2 and half‐wave potential of 850 mV (vs. RHE). In addition, the catalyst 0.5Co‐NC‐CeO2 also possesses a robust durability, that is the half‐wave potential exhibits a negative shift of only 17 mV after 1000 cycles. The enhanced ORR performance can be attributed to the synergistic effect among Co, the nitrogen‐doped carbon layer and CeO2. The results demonstrated here have implications in designing non‐Pt ORR catalysts.

Ag–CeO2 Composite Aerogels as Photocatalysts for CO2 Reduction

“…Here, CeO 2 is selected as the semiconductor phase while Ag is selected as the plasmonic sensitizer. CeO 2 has been reported as a good photocatalyst or cocatalyst. − However, like TiO 2 , CeO 2 suffers from low light absorption in the visible light range due to its wide band gap. Ag is known to have a strong SPR effect and has been adopted in various plasmon-enhanced photocatalytic reactions. , If one can construct a composite Ag–CeO 2 aerogel with the features of abundant Ag/CeO 2 interface, rich surface oxygen vacancies, and connected charge transfer pathways, it might offer a higher activity for gas-phase photocatalytic conversion of CO 2 .…”

A Review on Ceo2‐Based Electrocatalyst and Photocatalyst in Energy Conversion

“…A hierarchical CeO 2 @MnO 2 core–shell composite and multiple hollow CeO 2 sphere decorated MnO 2 microflower were constructed by Yang et al to catalyze ORR. [ 75–78 ] The enhanced catalytic performance was simply ascribed to the synergetic effect of CeO 2 and MnO 2 . Also, porous hexagonal FeCo 2 O 4 /CeO 2 heterostructures were prepared.…”

“…For both Co‐doped CeO 2 or Co‐doped carbon, the ORR catalytic activities of catalysts are significantly improved. [ 77,78 ] Similarly, Sivanantham et al constructed CeO 2 supported Co in N‐doped carbon nanorods and ascribed the improved ORR activity to the synergistic effect of Co and coexistence of Ce 3+ and Ce 4+ in CeO 2 . [ 79 ] Although Yu et al considered the similar performance that originates from the synergistic effect between CeO 2 nanoparticles and N‐doped carbon.…”

“…The onset potential and half‐wave potential of CeO 2 /NC [ 68 ] , CeO 2 /CePO 4 @NPC, [ 80 ] CeO 2 @MnO2, [ 75 ] CeO 2 /MnO 2 , [ 76 ] FeCo 2 O 4 /CeO 2 , [ 53 ] Co 2 P–NPC–CeO 2 , [ 81 ] Co–NC–CeO 2 , [ 77 ] CeO 2 /Co@NC, [ 58 ] and CeO 2 @Fe,S,N‐C [ 82 ] for ORR.…”

Evaluating the Growth of Ceria-Modified N-Doped Carbon-Based Materials and Their Performance in the Oxygen Reduction Reaction

“…; Table S5: Deconvolution results of N 1s XPS spectra of CeO 2 –CN–600, CeO 2 –CN–800, CeO 2 –CN–1000. References [ 64 , 65 , 66 , 67 , 68 , 69 ] are cited in the supplementary materials.…”