Co-ordination chemistry of palladium cations in Pd-H-ZSM-5 as revealed by FTIR spectra of adsorbed and co-adsorbed probe molecules (CO and NO)

文献情報

出版日 2004-04-23

DOI 10.1039/B401934B

インパクトファクター 3.676

著者

K. Chakarova, E. Ivanova, K. Hadjiivanov, D. Klissurski, H. Knözinger

原文を見る

要旨

Low temperature CO adsorption on a Pd-H-ZSM-5 sample results in formation of Pd3+(CO)2 species (2221 and 2200 cm−1). The dicarbonyl structure has been proven by coadsorption of 12CO and 13CO: mixed Pd3+(13CO)(12CO) species absorb at 2210 and 2158 cm−1. Evacuation of the sample at increasing temperatures leads to reduction of palladium and formation of different (poly)carbonyls of Pd2+, followed by Pd+–CO (2126 cm−1) and Pd0–CO (2105 cm−1) species. Adsorption of NO on the activated sample leads mainly to formation of Pd2+–NO linear nitrosyls (1881 cm−1), a small amount of NO+ (2137 cm−1), and Pd2+(H2O)(NO) species (1839 cm−1). Coadsorption of NO and O2 results in formation of (i) species typical of the H-ZSM-5 support (NO+, N2O3, NO2 and N2O4) and (ii) nitrates formed with the participation of palladium. Coadsorption of NO and excess CO results in appearance of mixed carbonyl–nitrosyl species of Pd2+ (νCO at 2146 cm−1 and νNO at 1813–1791 cm−1). The latter are decomposed easily losing their CO ligand. The results suggest a high coordinative unsaturation of the cationic palladium sites in Pd-H-ZSM-5.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.