Recent Progress in Carbon-based Materials of Non-Noble Metal Catalysts for ORR in Acidic Environment

Catalytic Upgrading of Bio‐Based 5‐Hydroxymethylfurfural to 2,5‐Dimethylfuran with Non‐Noble Metals

“…Carbon materials are often used as carriers to prepare some supported metal catalysts due to their large pore volume, high surface area, chemical inertness, and good mechanical and thermal stability. [48][49][50] For example, Gyngazova et al [51] used a wetness impregnation method to prepare a series of Ni/C catalysts with different nickel loadings. Among them, after reaction at 180 C for 2 h, the HMF conversion rate and DMF yield of 10 wt% Ni/C catalyst are 100% and 75%, respectively.…”

Inorganic non-carbon supported Pt catalysts and synergetic effects for oxygen reduction reaction

“…33,34 There have been a number of reviews of carbon-based materials as supports for ORR electrocatalysis. [35][36][37][38][39][40][41][42] However, the most typical drawbacks of carbon-based materials are the dissolution/ripening of Pt particles and the corrosion of carbon supports under the conditions of oxygen enriched electrochemical operation, leading to severe ORR performance degradation. 6,16,21,43,44 Therefore, a robust support material is crucial in protecting Pt nanoparticles against dissolution and aggregation in both physical and chemical ways to maintain or even enhance the catalytic activity of the catalysts for ORR.…”

Advances and Perspective of Noble-Metal-Free Nitrogen-Doped Carbon for pH-Universal Oxygen Reduction Reaction Catalysts

“…Followed by a successful improvement of ORR activity and stability of macrocyclic compounds using heat treatment, many studies have focused on developing Pt-free electrocatalysts within the past decade. − Among the Pt-free electrocatalysts, noble-metal-free nitrogen-doped carbon (M-N/C with M = Ni, Co, Mn, Fe) has drawn massive attention by virtue of its earth abundance, tunable electronic structure, high surface area, and tailored chemical composition, which improve the corresponding ORR activity. − In alkaline conditions, most of these M-N/C electrocatalysts have exhibited comparable ORR performance to Pt-based electrocatalysts . Nevertheless, their activities in neutral and acidic conditions are still insufficient, thus limiting their application in electrochemical-based devices that require acidic and neutral environments. − …”

“…Some reviews have summarized the performance of Pt-free electrocatalysts in certain pH conditions, namely, alkaline, neutral, and acidic conditions. ,,− Nonetheless, there are no reviews discussing ORR electrocatalysts, especially M-N/C catalysts, that work optimally under all pH conditions (denoted as pH-universal ORR electrocatalysts). This review outlines the recent advanced progress of M-N/C ORR electrocatalysts suitable for wide pH ranges.…”

“…23 Nevertheless, their activities in neutral and acidic conditions are still insufficient, thus limiting their application in electrochemical-based devices that require acidic and neutral environments. 24 Some technical challenges and insufficient understanding are still impeding the applications of M-N/C catalysts in all pH conditions. For instance, it is widely understood that the type of active site greatly affects the catalysts' ORR activities.…”