The nature of phase separation in a Ru–Sn–O ternary oxide electrocatalyst

Abstract

A phase stability diagram of ruthenium-zirconium oxide (Ru-Sn-O) was constructed by a combination of ab initio density functional theory and thermodynamic calculations. Results suggest that the phase separation/segregation that has been reported in the literature for the RuO(2)-SnO(2) system is through a typical spinodal decomposition mechanism. Ru(0.45)Sn(0.55)O(2) films were prepared by thermal co-decomposition of precursors at 500 °C for varied duration. Quantitative phase analyses of the prepared films based on X-ray diffraction and high-resolution transmission electron microscopy confirmed the spinodal nature of the phase separation. The present fundamental study provides a theoretical guideline for the phase and microstructure design of Ru-Sn-O based mixed oxides for electrocatalysis applications.

A New Composite Support for Pd Catalysts for Ethylene Glycol Electrooxidation in Alkaline Solution: Effect of (Ru,Sn)O2 solid solution

“…The d-spacing of (11 0) plane decreases from 3.352 to 3.350 Å with the addition of RuO 2 to SnO 2 . Considering the smaller size of Ru compared with that of Sn (0.69 vs. 0.71 Å), the positive shift of Bragg angles and the decrease in d-spacing indicate the formation of (Ru,Sn)O 2 solid solution, consistent with the previous results in literature [34]. 0 0), (2 2 0) and (3 11) planes of Pd, respectively.…”

“…Moreover, the d-spacing of some grains in Pd/RuO 2 -SnO 2 /C (in Fig. 2f) is 0.333 nm, in good agreement with the reported d-spacing of the (11 0) plane of SnO 2 -based solid solution in literature [34]. Fig.…”

On the abilities and limitations of the linear, exponential and combined models to describe the temperature dependence of the excess Gibbs energy of solutions

“…4. This is in full agreement with Calphad assessments performed so far: there is a large number of systems known with a high-T artifact due to the linear model [10][11][12][13][14], while there is no system known so far with a low-T artifact of the exponential model among the systems studied by full Calphad assessment and properly giving the resulting data [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] (see Table 6). Based on this, the statement that the exponential model is not used as it might lead to a low-T artifact, and therefore instead a linear model is used [42] is not a wise strategy of Calphad assessment.…”

Adding a Spinodal Decomposition Retarder: An Approach to Improving Electrochemical Properties of Ruthenium–Tin Complex Oxides

“…4 (in the unit of kilo Joules per mole of atoms) using an exponential temperature dependency of interaction parameter. 20,22 ( …”

“…This is also a challenge for many other RuO 2 -based complex oxides that are characteristic with a large driving force for spinodal decomposition. 19,20,22 In the present study, we have developed a novel scalable approach to retarding spinodal decomposition in the synthesis of Ru-Sn-O by c Present address: International Business Machines a thermal decomposition process. We introduced a certain amount of preformed nano-crystalline SnO 2 into the final precursor mixture used to prepare the Ru-Sn-O coating; the added SnO 2 effectively retarded spinodal decomposition of an initial (Ru 1-x ,Sn x )O 2 solid solution phase during the thermal treatment.…”