In Situ Growth of Ceria on Cerium–Nitrogen–Carbon as Promoter for Oxygen Evolution Reaction

Abstract

developing efficient and economical catalysts comprised of easily obtained materials for the OER is becoming very crucial for water splitting devices, in which the water-splitting catalysts made up of earthabundant elements have been paid a lot of attention. [2] Layer double hydroxide (LDH,posed of layers of divalent and trivalent metal cations coordinated to hydroxide anions, with guest anions intercalated between the layers, [3] displaying a promising structure for efficient electrocatalysts. It has been confirmed that exfoliated LDH shows higher electrocatalytic activity for the OER in alkaline environments than commercial precious metal based catalysts, [4] 3D self-supported LDH based materials showed outstanding catalytic activity and lifetime for OER, [5] and trinary NiCoFe-LDH exhibited an enhanced bifunctional performance on electrocatalysis. [6] Growing enthusiasm is devoted to optimizing the structure and composition of LDH materials themselves. However, studies on hybrid structure formed with other materials (such as carbon materials) almost lack of creativity and deep interpretation, especially for the effects of promoter acts on this process.Pure carbon materials exhibit scarcely any activity for the OER. [7] Alternatively, hybrid electrocatalysts of transition metal compounds with carbon materials (e.g., carbon nanotubes, [8] porous carbon, [8b,9] and graphene oxide (GO) [10] ) have been extensively investigated to improve the electrocatalytic activity for the OER, where carbon materials play a role of a promoter, most of the time. Beyond that, metal-nitrogen-carbon (MNC) materials are jumping into our sight as the greatest potential electrocatalysts. [11] The active sites are ascribed to central metal ions stabilized by nitrogen functional groups on carbonaceous surfaces, showing distinct interactions with oxygen molecules and the intermediates. [12] On the other hand, cerium-based materials have been reported to have the reversible surface oxygen ion exchange, good electronic/ionic conductivity, and high oxygen-storage capacities because of the flexible transition between the Ce 3+ and Ce 4+ oxidation states. [13] Recently, Li's group developed a novel electrocatalyst for OER by supporting FeOOH/CeO 2 heterolayered nanotubes on nickel foam and exhibited high performance. [14] They also demonstrated the unique high oxygen-storage capacitance properties of CeO 2 , such that CeO 2 can straightway absorb the oxygen produced Rational design and controlled synthesis of a promoter is a unique and more widely applicable approach to materials development for significant energy applications such as electrocatalytic oxygen evolution reaction. This study reports a novel promoter based on ceria in situ growth on cerium-nitrogencarbon (CeO 2 @CeNC) for an oxygen evolution electrocatalyst. Composited with NiFe-LDH (optimal mass ratio of layer double hydroxide (LDH) and CeO 2 @CeNC is 2), the hybrid material (NiFe-LDH/CeO 2 @CeNC) exhibits excellent activity for oxygen evolution superior to those of most n...

A Review of Transition Metal Oxygen-Evolving Catalysts Decorated by Cerium-Based Materials: Current Status and Future Prospects

“…The CeBM-decorated transition metal oxygen-evolving catalysts provide the full extent of synergy between CeBM and the substrate or parent catalyst, promoting formation and transformation of the intermediates, facilitating mass and charge transfer, and thus improving the overall reaction kinetics and efficiency. Generally, multiple strategies have been involved, such as: solvothermal, 41 precipitation, 42 MOF derivation, 43 electrodeposition 44 and self-assembly strategy, 45 etc. Below we have summarized and discussed the representative synthetic approaches based on different material types, including: TMOs, TMCs, TMPs, and TMBs (Table 1).…”

Gold Nanoparticles on Nanosheets Derived from Layered Rare-Earth Hydroxides for Catalytic Glycerol-to-Lactic Acid Conversion

“…). − The compositions, sizes, and various (e.g., optical, magnetic, and catalytic) properties of LREHs can be designed by modulating RE 3+ ions sequentially arranged in stacked hydroxide layers or by changing interlayered anions. Rare-earth oxides and hydroxides have been widely used as promoters to improve the dispersion of supported metal nanoparticles and the oxygen storage capacity of catalysts, which can enhance the catalytic efficiency. − The LREH materials with rare-earth hydroxide layers may also be explored as high-performance catalysts or catalyst precursors. However, in the catalysis field, they have received little attention compared with the traditional hydrotalcite compounds such as MgAl–LDH .…”

CeO2 decorated bimetallic phosphide nanowire arrays for enhanced oxygen evolution reaction electrocatalysis via interface engineering

“…3d) shows a series of peaks, in which the peaks at 885.8 and 903.8 eV belong to Ce 3+ , and the remaining peaks at 882.2, 888.2, 908.0, and 916.7 eV are ascribed to Ce 4+ , revealing the co-existence of Ce 3+ and Ce 4+ species. 58,59 The presence of Ce 3+ and Ce 4+ species suggests the presence of rich oxygen vacancies, which is further proved by the O 1s XPS spectrum (Fig. 3e).…”