Effect of TiO2 Drying Conditions on the Catalytic Activity of Pt for Ammonia Synthesis from NO−H2

• Published in: ChemistrySelect (Weinheim) 2024-04, Vol.9 (14), p.n/a
• Main Authors: Chaudhari, Chandan, Manaka, Yuichi, Nanba, Tetsuya
• Format: Article
• Language: English
• Subjects: Ammonia; Nitrogen oxides; Platinum; Supported catalysts
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202304789

The effect of drying conditions on the physicochemical and catalytic properties of TiO2 were examined for NO to ammonia reaction. TiO2 prepared by different drying conditions such as evaporation (EP), evaporation under reduced pressure (ER) and evaporation under freeze drying conditions (EF) was used for support for Pt loading. At low temperature (below 175 °C), the order for ammonia formation was Pt/TiO2(ER)>Pt/TiO2(EP)>Pt/TiO2(EF). Notably, Pt/TiO2(ER) catalyst was more effective than Pt/TiO2 prepared from commercially available TiO2. The characterization of these catalysts revealed that rutile‐rich phase TiO2, high Pt dispersion and moderate acidic sites were influential factors for ammonia formation. TiO2 drying conditions modified surface properties of TiO2 and consequently, catalytic activity for ammonia formation. TiO2 was synthesized by sol‐gel method and dried by using different drying conditions such as evaporation (EP), evaporation under reduced pressure (ER), evaporation under freezing drying conditions (EF). CO‐chemisorption revealed that Pt dispersion on TiO2(ER) support was higher than that of EP, EF and commercial TiO2 (ST) which led to high activity for nitrogen oxide to ammonia reaction.