# The Ethanol Oxidation Reaction Performance of Carbon-Supported PtRuRh Nanorods
## 2 Experimental Section
### Characterizations of the Catalysts  
The atomic compositions of catalysts were characterized by a field emission scanning electron microscope (JSM7000F) and an X-ray energy dispersive spectrometer (SEM-EDS, Bruker) operated at 15 kV. The phases and structures of prepared catalysts were analyzed by the X-ray diffraction (XRD) with CuK\(\alpha\) radiation operated 40 kV and 25 mA at a scan rate of 3\({}^{\circ}\) min\({}^{-1}\). In order to calculate d-spacing, [PERSON]'s law was applied:  
\[\mathrm{n}\lambda=2 dsin\theta \tag{6}\]  
where n is positive integer, \(\lambda\) is the wavelength of radiation source, \(\theta\) is the diffraction angle and d is the d-spacing. In addition, for the face-centered cubic crystal style, the lattice parameter can be determined by the relationship of Equation (7):  
\[d=\frac{a}{\sqrt{\mathrm{l}^{2}+\mathrm{m}^{2}+\mathrm{n}^{2}}} \tag{7}\]  
where l, m and n are the Miller index, d is the d-spacing value and a is the lattice parameter. In order to obtain the grain size, [PERSON]'s equation was applied [49]:  
\[\tau=\frac{\mathrm{K}\lambda}{\betaCOS\theta} \tag{8}\]  
where the \(\tau\) is mean grain size, K is constant, \(\lambda\) is the wavelength of radiative source, \(\beta\) is the full width at half maximum of the base peak and\(\theta\) is the diffraction angle. The morphologies of catalysts were confirmed by high-resolution transmission electron microscopy (HRTEM, JOEL-2100) operated at 160 kV. The catalysts powders were prepared by ultrasonically suspending in IPA. Afterward, the suspension was then dropped on 200 mesh copper grids. The surface chemical states of various catalysts were analyzed by X-ray photoelectron spectroscopy (XPS, Thermo VG Scientific Sigma Probe) using an AlK\(\alpha\) radiation at a voltage of 20 kV and a current of 30 mA. The surface compositions and chemical states of the samples are calculated by integral of each peak and a combination of Lorentzian and Gaussian lines was applied to fit the experimental curves. C 1s peak at 284.6 eV was used as an internal standard to determine the accurate binding energies. The surface species of the prepared catalysts were characterized by the H\({}_{2}\)-temperature-programmed reduction (TPR). The variations of hydrogen contents during the flowing of the reduction gas are detected by a thermal conductivity detector (TCD). The sample of 0.1 g was reduced by a flow of 20% H\({}_{2}\) in N\({}_{2}\) at the flow rate of 50 mL min\({}^{-1}\) while raising the temperature from 150 to 600 K at the heating rate of 7 K min\({}^{-1}\). Electrochemical measurements through a CH Instruments Model 611c device were operated to analyze the performance of prepared catalysts. The counter and reference electrodes were Pt plate and saturated calomel electrode (SCE), respectively. The catalysts in IPA and Nafion solution (5 wt. %, DuPont) were dispersed and dropped on a glass carbon electrode as working electron. CO-stripping was operated by purging CO gas in 0.5 M H\({}_{2}\)SO\({}_{4}\) for 30 min before the experiment; while operating, CO was kept purging at \(-\)0.1 V (vs. SCE) for 30 min, then CO-stripping was measured between \(-\)0.3 and 0.76 V (vs. SCE) at the rate of 50 mV s\({}^{-1}\) in N\({}_{2}\) saturated 0.5 M H\({}_{2}\)SO\({}_{4}\) The electrochemically active surface area calculated form CO-stripping (ECSA\({}_{\rm CO}\)) is defined by the Equation (9):  
\[ECSA_{\rm CO}=\frac{Q_{\rm CO}}{[Pt]\times 0.42} \tag{9}\]  
where [Pt] presents the Pt loading on the electrode, Q\({}_{\rm CO}\) indicates the charge for CO-desorption and 0.42 is assuming that the oxidation of a CO monolayer requires 0.42 mC/m\({}^{2}\)[50]. Cyclic voltammograms (CV) were swept between \(-\)0.24 and 1.0 V (vs. SCE) at the rate of 50 mVs\({}^{-1}\) in 0.5 M H\({}_{2}\)SO\({}_{4}\) purged with N\({}_{2}\) for 30 min to ensure the electrolyte is N\({}_{2}\)-saturated. The ECSA by H-adsorption (ECSA\({}_{\rm H}\)) [50; 51] was calculated by integrating the areas of hydrogen desorption at 0-0.4 V (Q\({}_{\rm H}\)).