Highly Stable Pt-Based Oxygen Reduction Electrocatalysts toward Practical Fuel Cells: Progress and Perspectives

Abstract

The high cost and poor reliability of cathodic electrocatalysts for the oxygen reduction reaction (ORR), which requires significant amounts of expensive and scarce platinum, obstructs the broad applications of proton exchange membrane fuel cells (PEMFCs). The principles of ORR and the reasons for the poor stability of Pt-based catalysts are reviewed. Moreover, this paper discusses and categorizes the strategies for enhancing the stability of Pt-based catalysts in fuel cells. More importantly, it highlights the recent progress of Pt-based stability toward ORR, including surface-doping, intermetallic structures, 1D/2D structures, rational design of support, etc. Finally, for atomic-level in-depth information on ORR catalysts in fuel cells, potential perspectives are suggested, such as large-scale preparation, advanced interpretation techniques, and advanced simulation. This review aims to provide valuable insights into the fundamental science and technical engineering for practical Pt-based ORR electrocatalysts in fuel cells.

Recent Progress on Durable Metal‐N‐C Catalysts for Proton Exchange Membrane Fuel Cells

“…Initial fuel cell testing typically reveals a 40 % to 80 % performance decline within the first 100 hours. This quick falls far short of the DOE′s durability requirements for light‐duty vehicle applications (8,000 hours with 10 % performance degradation) [17] …”

“…[6,[13][14][15] Although these catalysts exhibit superior performance under certain conditions, their durability in PEMFCs is far from satisfactory. [3,16,17] Commonly, chronoamper-ometry at a cell voltage between 0.4 and 0.7 V vs. RHE is used to determine the stability of FeÀ NÀ C. Initial fuel cell testing typically reveals a 40 % to 80 % performance decline within the first 100 hours. This quick falls far short of the DOE's durability requirements for light-duty vehicle applications (8,000 hours with 10 % performance degradation).…”

“…This quick falls far short of the DOE's durability requirements for light-duty vehicle applications (8,000 hours with 10 % performance degradation). [17] Herein, several degradation mechanisms inherent to MÀ NÀ C catalysts, including carbon corrosion, metal leaching, H 2 O 2 attack, nitrogen protonation, and micropore inundation, are first introduced. [1,[19][20][21][22] Carbon corrosion, metal leading, and H 2 O 2 attack stand out as the most important causes of catalyst deterioration.…”

“…Transition M−N−C catalysts with explicit M−N x coordination active sites embedded in the basal plane of carbon supports exhibit the most promising characteristics among the non‐PGM ORR catalysts developed over the past decade [6,13–15] . Although these catalysts exhibit superior performance under certain conditions, their durability in PEMFCs is far from satisfactory [3,16,17] . Commonly, chronoamper‐ometry at a cell voltage between 0.4 and 0.7 V vs. RHE is used to determine the stability of Fe−N−C.…”

Collaborative Anchoring of Pt Nanoparticles and Metal Oxide Nanoparticles on N-Doped Carbon as Catalysts for Oxygen Reduction

“…Pt/C consistently shows problems related to carbon corrosion and weak interactions between Pt and C. − To solve these problems, researchers have proposed a strategy involving the introduction of metal oxides (MO) into Pt-based catalysts. − MO is also considered an ideal support to promote the homogeneous growth of Pt micronuclei and enhance the uniform dispersion of Pt particles . By understanding the reaction mechanism and carrying out targeted design and synthesis work, high-activity and durable Pt-MO catalysts were developed.…”