Dimensionally Stable Ru/Ir/TiO₂-Anodes with Tailored Mesoporosity for Efficient Electrochemical Chlorine Evolution

Abstract

Chlorine evolution is one of the most important electrochemical reactions applied in industry. We present a method for the synthesis of chlorine evolution catalysts with improved performance. The performance increase results from the introduction of controlled mesoporosity into the pore system of Ru- and Ir-containing TiO2 catalysts by pore templating with micelles of amphiphilic block-copolymers. Micelle-templated TiO2-based catalysts were synthesized with loadings up to 15 wt % of either Ru, Ir, or a combination of both active metals. The catalysts’ walls are composed of nanocrystalline mixed oxides with rutile structure. The templated mesopores are about 10 nm in size and form an ordered cubic pore system with good pore connectivity. All studied catalysts are active in chlorine evolution. Adding templated mesoporosity doubles the catalyst performance at identical catalyst composition. The influences of film thickness, composition, and porosity of the developed catalytic coatings on the catalytic performance are discussed.

Crystalline nickel, cobalt, and manganese antimonates as electrocatalysts for the chlorine evolution reaction

“…RuTiO x films with the same molar loading (~ 1.5 μmol cm -2 ) as the MSb 2 O x films were prepared by drop casting 4 μL cm -2 of a 0.11 M RuCl 3 and 0.26 M TiCl 4 solution in ethanol onto ATO, followed by drying on a hot plate at 400 °C. 3 The RuTiO x was annealed at 500 °C for 1 h in a muffle furnace. 3 The samples were cleaved into pieces that had exposed ATO regions, and In-Ga eutectic was scribed on the ATO.…”

“…3 The RuTiO x was annealed at 500 °C for 1 h in a muffle furnace. 3 The samples were cleaved into pieces that had exposed ATO regions, and In-Ga eutectic was scribed on the ATO. The electrode support consisted of a tinned Cu wire that was threaded through a glass tube.…”

Nafion‐Free Carbon‐Supported Electrocatalysts with Superior Hydrogen Evolution Reaction Performance by Soft Templating

“…The regular pore spacings derived from FFT amount to 14.5 nm parallel and 5.5 nm normal to the substrate surface. The observed ellipsoidal distortion of the pore shape is a common phenomenon reported for oxide (TiO 2 , Pd/TiO 2 , IrO 2 , Ru/Ir/TiO 2 , MgO, ZnO, NiO, SnO 2 ) and carbon films templated by polymer micelles . The distortion results from uniaxial shrinking normal to the substrate surface upon drying of the deposited films …”

Activity‐Stability Volcano Plots for Material Optimization in Electrocatalysis

“…RuO 2 with the (110) facet as most stable surface termination [69] corresponds to the active component of dimensionally stable anodes (DSA) [40] that are employed in the chlor-alkali process. [70] Typical overpotentials in industrial electrolysis are about 0.10 V. [41,71] In case of the RuO 2 (110) electrode, a suitable model system for DSA, [71] the Heyrovsky step is rate determining under these conditions (cf. Figure 2c) so that the activity-stability volcano plot (cf.…”