Synthesis and characterization of Ti_0.9Ir_0.1O₂-activated carbon composite as a promising support for catalysts in electrochemical energy conversion

Abstract

Constructing robust support plays a key role in governing the overall catalytic efficiency of metal-based catalysts for electrochemical reactions in sustainable energy-related conversion systems. We herein use a solvothermal method to assemble Ti0.9Ir0.1O2-Activated C composites, exhibiting high surface area and electrical conductivity compared to the pure TiO2 material. The material characterisations and electrochemical behaviours of the as-obtained composites are systemically studied by XRD, FE-SEM-EDX mapping, FT-IR, XPS, BET, four-point technique, cyclic voltammetry, etc Notably, the effect of composition on the physical and electrochemical properties of the as-made composites is also explored, which indicated the significant improvement in surface area and electrical conductivity with increasing carbon content, while a reverse trend is observed in the electrochemical durability. Among all studied composites, the Ti0.9Ir0.1O2-Activated C (50:50 wt%) composite can be a suitable support for metal-based catalysts due to its balance in physical properties (electrical conductivity of 1.5 S cm−1 and surface area of 152.12 m2 g−1) and electrochemical corrosion resistance (high durability after 2000-cycling ADT). This study can open up an efficient strategy to enhance the catalytic performance of electrochemical processes.

Enhanced formic acid electro-oxidation reaction over Ir,N-doped TiO2-supported Pt nanocatalyst

“…Additionally, the location of the diffraction peaks in the XRD pattern of the Ir,N-doped TiO 2 was slightly shifted to a more positive 2θ angle than the standard TiO 2 structures, being assigned to the different ionic radius of Ti 4+ (0.605 Å) and Ir 4+ (0.625 Å) when introducing Ir element into the TiO 2 structure [9,38,39]. Furthermore, N 3− ions (0.14 Å) can replace O 2− ions (0.13 Å) in the TiO 2 lattice, resulting in the similar length of the Ti-N and Ti-O bond (2.081 Å and 2.002 Å, respectively) [40].…”

“…Furthermore, N 3− ions (0.14 Å) can replace O 2− ions (0.13 Å) in the TiO 2 lattice, resulting in the similar length of the Ti-N and Ti-O bond (2.081 Å and 2.002 Å, respectively) [40]. The average crystallite size of asobtained materials was also calculated to further assess the influence of nitrogen in the formation of the TiO 2 lattice using the Debye-Sherrer formula [39][40][41]:…”

“…Another peak at ∼2400 cm −1 was due to the absorption of atmospheric CO 2 molecules on the metallic cations [44,45]. A vibration band at ∼600-400 cm −1 was attributable to the stretching vibration of the Ti-O and/or Ti-O-M bond [39,42,43]. Compared to the Ir-doped TiO 2 , the FT-IR spectroscopy of the Ir,N-doped TiO 2 material shows weak absorption peaks at ∼1388, 1196, and 1116 cm −1 of the Ti-N vibration [46,47], as illustrated in figure 2(b).…”