Academia.eduAcademia.edu

Figure 7 – uploaded by Ganpurev Adilbish

See full PDFdownloadDownload figure
Fig. 7. A comparison of MOR activity of the Pt/C and Pt-Ru/C commercial and Pt/C-Au@CeO,-Pt electrocatalysts: (a) MOR mass activity and corresponding durability up to 1000 sequential cycles obtained in N-saturated solution of 0.5 M H2SO,+ 1 M CH30H electrolyte at a sweep rate of 50 mV/s at 25 °C. On the other hand, the EIS is also tested in Nz-saturated solution of 0.5 M H2S0O,+1M CH3OH electrolyte in order to measure the internal resistance of all of the as-prepared electrocatalysts. The EIS spectra are analyzed using Nyquist plots (Fig. 8b), which are fit- ted with an equivalent circuit, as given in Fig. S16, where, R, indi- cates the solution resistance, Ry presents the charge transfer resistance and CPE is a constant phase element. All EIS spectra con- tain a semicircle portion, with the small diameter of the semicircle (small R,,) demonstrates low charge transfer resistance of the MOR activity. From the given equivalent circuit, the Re value is calcu- lated to be 86Q for Pt/C-Au@CeO,-Pt, 106 Q for Pt/C-CeO,-Pt, 127 Q for Pt/C-Pt and 155 Q for Pt/C electrocatalysts, respectively. In general, the introduction of CeOz-based materials to Pt/C cata- lyst could contribute to the decrease of R,, at the interface between working electrocatalyst and electrolyte, in particular, the Pt/C-Au@CeO2-Pt shows the smallest internal resistance among all of the as-prepared electrocatalysts. For this reality, the role of each catalyst layer in the Pt/C-Au@CeO,-Pt structure is clarified as follows. The Pt EPD layer serves as main catalyst as the system In order to evaluate the CO tolerance of all of the as-prepared electrocatalysts, the CO stripping voltammetry is measured in No-saturated solution of 0.5M H,SO,4. From the CO stripping voltammetry results of the Pt/C, Pt/C-Pt, Pt/C-CeO2-Pt and Pt/C-Au@CeO>-Pt electrocatalysts (Figs. S15(a-d)), the absence of the hydrogen desorption region in the first cycle is that hydrogen adsorption is suppressed due to CO poisoning. In the second cycle, the appearance of the hydrogen desorption region can be clearly seen after the successive oxidation of surface adsorbed CO species

Figure 7 A comparison of MOR activity of the Pt/C and Pt-Ru/C commercial and Pt/C-Au@CeO,-Pt electrocatalysts: (a) MOR mass activity and corresponding durability up to 1000 sequential cycles obtained in N-saturated solution of 0.5 M H2SO,+ 1 M CH30H electrolyte at a sweep rate of 50 mV/s at 25 °C. On the other hand, the EIS is also tested in Nz-saturated solution of 0.5 M H2S0O,+1M CH3OH electrolyte in order to measure the internal resistance of all of the as-prepared electrocatalysts. The EIS spectra are analyzed using Nyquist plots (Fig. 8b), which are fit- ted with an equivalent circuit, as given in Fig. S16, where, R, indi- cates the solution resistance, Ry presents the charge transfer resistance and CPE is a constant phase element. All EIS spectra con- tain a semicircle portion, with the small diameter of the semicircle (small R,,) demonstrates low charge transfer resistance of the MOR activity. From the given equivalent circuit, the Re value is calcu- lated to be 86Q for Pt/C-Au@CeO,-Pt, 106 Q for Pt/C-CeO,-Pt, 127 Q for Pt/C-Pt and 155 Q for Pt/C electrocatalysts, respectively. In general, the introduction of CeOz-based materials to Pt/C cata- lyst could contribute to the decrease of R,, at the interface between working electrocatalyst and electrolyte, in particular, the Pt/C-Au@CeO2-Pt shows the smallest internal resistance among all of the as-prepared electrocatalysts. For this reality, the role of each catalyst layer in the Pt/C-Au@CeO,-Pt structure is clarified as follows. The Pt EPD layer serves as main catalyst as the system In order to evaluate the CO tolerance of all of the as-prepared electrocatalysts, the CO stripping voltammetry is measured in No-saturated solution of 0.5M H,SO,4. From the CO stripping voltammetry results of the Pt/C, Pt/C-Pt, Pt/C-CeO2-Pt and Pt/C-Au@CeO>-Pt electrocatalysts (Figs. S15(a-d)), the absence of the hydrogen desorption region in the first cycle is that hydrogen adsorption is suppressed due to CO poisoning. In the second cycle, the appearance of the hydrogen desorption region can be clearly seen after the successive oxidation of surface adsorbed CO species

Related Figures (7)

Fig. 1. The schematic sequence for the fabrication of the Pt/C-Au@CeO2-Pt working electrocatalyst.
Fig. 1. The schematic sequence for the fabrication of the Pt/C-Au@CeO2-Pt working electrocatalyst.
Fig. 2. (a) The HRTEM image and (b) particle size distribution histogram of as-synthesized Au colloidal core. (c) HRTEM image of as-calcined Au@CeO2 nanoparticles. (d) The HRTEM image of a selected Au@CeO2 nanoparticle. The HRTEM elemental mapping of (e) Au, (f) Ce and (g) O components. (h) The HRTEM-EDS compositional line-scanning profile of Au@CeO, nanoparticle. (i) The lattice fringes of the (1 1 1) plane of CeO, shell and (1 1 1) plane of Au core, respectively. (j) The FESEM image of as-calcined Au@CeO, nanoparticles.
Fig. 2. (a) The HRTEM image and (b) particle size distribution histogram of as-synthesized Au colloidal core. (c) HRTEM image of as-calcined Au@CeO2 nanoparticles. (d) The HRTEM image of a selected Au@CeO2 nanoparticle. The HRTEM elemental mapping of (e) Au, (f) Ce and (g) O components. (h) The HRTEM-EDS compositional line-scanning profile of Au@CeO, nanoparticle. (i) The lattice fringes of the (1 1 1) plane of CeO, shell and (1 1 1) plane of Au core, respectively. (j) The FESEM image of as-calcined Au@CeO, nanoparticles.
Fig. 3. (a) The UV-vis. spectra of Au (black) and Au@CeO, (red) solutions. (b) The XRD patterns of Au nanoparticles (pink), CeO2 (blue) and as-calcined Au@CeO nanocomposite (red). In Au@CeO XRD pattern, Au core peaks marked with (;) and CeO2 shell peaks marked with (*). The XPS analysis of as-calcined Au@CeO2 nanoparticles (c) full range, (d) Au 4f, (e) Ce 3d and (f) O 1s.
Fig. 3. (a) The UV-vis. spectra of Au (black) and Au@CeO, (red) solutions. (b) The XRD patterns of Au nanoparticles (pink), CeO2 (blue) and as-calcined Au@CeO nanocomposite (red). In Au@CeO XRD pattern, Au core peaks marked with (;) and CeO2 shell peaks marked with (*). The XPS analysis of as-calcined Au@CeO2 nanoparticles (c) full range, (d) Au 4f, (e) Ce 3d and (f) O 1s.
Fig. 4. (a) The HRTEM images of synthesized Pt catalyst nanoparticles, (b) the HRTEM images of a selected Pt catalyst and (c) the particle size distribution histogram fo synthesized Pt catalyst nanoparticles. (d) The HRTEM images of Pt/C composite catalyst, (e) the HRTEM images of a selected Pt/C composite nanoparticle and (f) the particl size distribution histogram of the Pt catalyst nanoparticles decorated on carbon black support.
Fig. 4. (a) The HRTEM images of synthesized Pt catalyst nanoparticles, (b) the HRTEM images of a selected Pt catalyst and (c) the particle size distribution histogram fo synthesized Pt catalyst nanoparticles. (d) The HRTEM images of Pt/C composite catalyst, (e) the HRTEM images of a selected Pt/C composite nanoparticle and (f) the particl size distribution histogram of the Pt catalyst nanoparticles decorated on carbon black support.
Fig. 5. FESEM surface images analysis of Pt/C-Au@CeO2-Pt working catalytic electrode: (a) the surface of the MPL layer of carbon cloth substrate, (b) after the spraying of Pt/C catalytic slurry, (c) after the spraying of Au@CeOj slurry and (d) after the EPD of synthesized Pt catalytic nanoparticles. The corresponding FESEM cross-sectional analysis: (e) an overview of FESEM cross-sectional observation, (f) FESEM-EDS cross-sectional elemental mapping of C, (g) Pt, (h) Au, (i) Ce and (j) O. (k) FESEM-EDS spectrum of Pt/C- Au@CeOQ>-Pt electrocatalyst.
Fig. 5. FESEM surface images analysis of Pt/C-Au@CeO2-Pt working catalytic electrode: (a) the surface of the MPL layer of carbon cloth substrate, (b) after the spraying of Pt/C catalytic slurry, (c) after the spraying of Au@CeOj slurry and (d) after the EPD of synthesized Pt catalytic nanoparticles. The corresponding FESEM cross-sectional analysis: (e) an overview of FESEM cross-sectional observation, (f) FESEM-EDS cross-sectional elemental mapping of C, (g) Pt, (h) Au, (i) Ce and (j) O. (k) FESEM-EDS spectrum of Pt/C- Au@CeOQ>-Pt electrocatalyst.
Fig. 6. (a) The cyclic voltammetry performances of Pt/C, Pt/C-Pt, Pt/C-CeO2-Pt and Pt/C-Au@CeO,-Pt working electrocatalysts obtained in Nj-saturated solution of 0.5} H2SO, electrolyte at a sweep rate of 50 mV/s at 25 °C and (b) the corresponding ECSA value. (c) The cyclic voltammetry curves of methanol electrooxidation reaction obtaine in N2-saturated solution of 0.5 M H2SO, + 1 M CH3OH electrolyte at a sweep rate of 50 mV/s at 25 °C and (d) the corresponding mass activity. The electrocatalytic durabilit tested in N>-saturated solution of 0.5 M H2SO, + 1 M CH3OH electrolyte at a sweep rate of 50 mV/s up to 1000 sequential cycles: (e) change in forward peak current densit and (f) the corresponding relative activity.
Fig. 6. (a) The cyclic voltammetry performances of Pt/C, Pt/C-Pt, Pt/C-CeO2-Pt and Pt/C-Au@CeO,-Pt working electrocatalysts obtained in Nj-saturated solution of 0.5} H2SO, electrolyte at a sweep rate of 50 mV/s at 25 °C and (b) the corresponding ECSA value. (c) The cyclic voltammetry curves of methanol electrooxidation reaction obtaine in N2-saturated solution of 0.5 M H2SO, + 1 M CH3OH electrolyte at a sweep rate of 50 mV/s at 25 °C and (d) the corresponding mass activity. The electrocatalytic durabilit tested in N>-saturated solution of 0.5 M H2SO, + 1 M CH3OH electrolyte at a sweep rate of 50 mV/s up to 1000 sequential cycles: (e) change in forward peak current densit and (f) the corresponding relative activity.
Fig. 8. (a) The comparison of CO stripping performance of Pt/C, Pt/C-Pt, Pt/C-CeO2-Pt and Pt/C-Au@CeO,-Pt working electrocatalysts. (b) The EIS Nyquist plots measured in N2-saturated solution of 0.5 M H2SO,+1M CH30H electrolyte at 25°C recording from 100 kHz to 0.05 Hz of as-prepared working electrocatalysts. (c,) The possible mechanism for methanol oxidation reaction on the Pt/C-Au@CeO>-Pt electrocatalyst and (c2) the active interface of Au@CeO2 core-shell structures.
Fig. 8. (a) The comparison of CO stripping performance of Pt/C, Pt/C-Pt, Pt/C-CeO2-Pt and Pt/C-Au@CeO,-Pt working electrocatalysts. (b) The EIS Nyquist plots measured in N2-saturated solution of 0.5 M H2SO,+1M CH30H electrolyte at 25°C recording from 100 kHz to 0.05 Hz of as-prepared working electrocatalysts. (c,) The possible mechanism for methanol oxidation reaction on the Pt/C-Au@CeO>-Pt electrocatalyst and (c2) the active interface of Au@CeO2 core-shell structures.
Related topics:
Chemical EngineeringChemistryCatalysisElectrophoresis depositionCore shell NanoparticlesMethanol oxidation reaction
580 California St., Suite 400
San Francisco, CA, 94104
© 2025 Academia. All rights reserved