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Currently, ruthenium oxide is considered a promising alternative to IR-based catalysts in proton exchange membrane water electrolyzers, but it still faces bottlenecks of limited durability and slow kinetics. On this basis, a two-dimensional amorphous heterogeneous Ac-Cr0 with universal grain boundaries (GBS) is established53ru0.47O2-δ displaces solid solutions to accelerate acid oxygen evolution reaction (OER) kinetics while prolonging its long-term stability. ac-cr0.53ru0.47O2-δ exhibits super-stability, at 1The 6 V vs RHE decreased the decomposition rate slowly, and the mass activity was 455 A GRU1, which was about 3. higher than that of synthetic RuO2 and commercial RuO2, respectively6 times and 59 times. Strong interaction of the CR-O-RU local unit with AC-CR053ru0.The synergy of specific two-dimensional structural features of 47O2-δ is the main reason for its enhanced stability. At the same time, high-density GB and shortened Ru-O bonds tailored to the amorphous crystalline structure and Cr-O-RU interaction modulate the adsorption and desorption rates of oxygen intermediates, thereby accelerating the overall acidic OER kinetics.
A) XRD spectra and B) AC-CR053ru0.47O2-δ and SYNEnlarged XRD spectra of RuO2. c、d) ac-cr0.53ru0.Typical TEM image of 47O2-δ, E) HRTEM image, F) Enlarged HRTEM image. g) TEM image, H) HRTEM image, i) SYNEnlarged HRTEM image of ruo2. j) ac-cr0.53ru0.47O2-δ and k) syn(101) surface intensity distribution of ruO2. l) XRD spectra of catalysts prepared with different CR Ru molar ratios. m) ac-cr0.53ru0.47O2-δ Element mapping of O, CR, and RU.
a) ac-cr0.53ru0.47o2-δ，syn.XPS survey spectra of RuO2 and B) Cr2O3. c) ac-cr0.53ru0.High-resolution CR 2P XPS spectra of 47O2-δ and Cr2O3. d) ac-cr0.53ru0.47o2-δ、syn.ruo2 and commHigh-resolution O 1S XPS spectra of RuO2. e) ac-cr0.53ru0.Normalized CR K-edge Xanes spectra and F) FT-Exafs spectra of 47O2-δ and references. G-J) WT analysis of CR foil, CRO3, CR2O3 and AC-CR053ru0.47o2-δ。
a) ac-cr0.53ru0.47o2-δ，syn.Normalized RU2 and RUk-edge Xanes spectra of references. b) ac-cr0.53ru0.47o2-δ，syn.FT-Exafs spectra of RUo2 and references. c) ac-cr0.53ru0.FT-Exafs fitting curve of 47O2-δ. d) ac-cr0.53ru0.47o2-δ，syn.ruo2 and commHigh-resolution RU 3P XPS spectra of RuO2. e) ac-cr0.53ru0.47o2-δ，syn.EPR spectrum of ruO2. f) ac-cr0.53ru0.Crystal structure of 47O2-δ. g-j) ru foil, comm ruo2、syn.ruo2 and ac-cr053ru0.WT analysis of 47O2-δ.
oer at 0Catalytic activity in 1 M HCO4 solution. a) ac-cr0.53ru0.47o2-δ、syn. ruo2、comm.Representative polarization curves for RuO2 and Cr2O3. b) The corresponding tafel slope. c) ac-cr0.53ru0.47O2-δ with SYN ruo2, comm.Comparison of J = 10 mA2 overpotential and Tafel slope of RuO2. d) ac-cr0.53ru0.Comparison of 47O2-δ with recently reported TOF of Ru-based catalysts. e) ac-cr0.53ru0.47o2-δ、syn.ruo2 and commMass activity of ruO2. f) CDL and G) AC-CR053ru0.47o2-δ，syn. ruo2, comm.ruo2 and cr2o3 in 1Nyquist plot at 5 V. h) ac-cr0.53ru0.Comparison of the geometric activity of 47O2-δ with other representative ruthenium-based catalysts.
a) ac-cr0.53ru0.47o2-δ and commWave phase diagram of ruo2. c) phase angle to ac-cr053ru0.47o2-δ and commResponse to the imposition potential of ruO2. ac-cr0.53ru0.High-resolution XPS spectra of 47O2-δ before and after OER testing: D) Cr 2P, E) RU3P, F) O 1S.
In summary, a two-dimensional amorphous heterogeneous AC-CR0 with a wide range of GB53ru0.47O2-δ substituted solid solution proved to be a highly active and stable OER electrocatalyst in acidic media. ac-cr0.53ru0.The overpotential of 47O2-δ is 239 mV, the reference current density is 10 mA, and the mass activity is 455 A Gru1, respectivelyruo2 and commruo2 is about 36 times and 59 times. ac-cr0.53ru0.The stability of 47O2-δ is also significantly higher than that of SYNruo2 and commruO2, after 40 h of operation, there was no overpotential increase. The high-density GB and amorphous crystal structure of the Ru O bond regulates the adsorption and desorption behavior of oxygen intermediates, which is conducive to faster OER kinetics. ac-cr0.53ru0.The abundant local units of Ru-O-Cr in 47O2-δ slow down the peroxidation of the RU active center by preferential oxidation of CR, thereby improving the stability. This study provides new insights into the origin of catalytic activity and the rational design of electrocatalysts for energy-related devices.
2d ruthenium–chromium oxide with rich grain boundaries boosts acidic oxygen evolution reaction kinetics - zhao - small - wiley online library