Dispersive XAFS Study on the Laser-Induced Reduction of a Rh ion complex; Presence of a Rh Intermediate in Direct Photoreduction

Saeki, Morihisa*; Matsumura, Daiju; Nakanishi, Ryuzo*; Yomogida, Takumi; Tsuji, Takuya; Saito, Hiroyuki*; Oba, Hironori*

Journal of Physical Chemistry C, 126(12), p.5607 - 5616, 2022/03

https://doi.org/10.1021/acs.jpcc.1c10160

The reaction mechanism of the direct photoreduction of a Rh ion complex to a Rh species induced by pulsed ultraviolet laser irradiation was studied using dispersive X-ray absorption fine structure (DXAFS) spectroscopy. The time-resolved X-ray absorption near edge structure (XANES) showed the absence of isosbestic points and suggested that more than two Rh species contribute toward the direct photoreduction of Rh. Analysis of the time-resolved XANES data by singular value deposition showed that the direct photoreduction involves three Rh species. Multivariate curve resolution by alternating least-squares analysis (MCR-ALS) of the time-resolved XANES data gave pure spectra and concentration profiles of the three Rh species. The Rh species were assigned to Rh, Rh, and Rh species based on the features of the pure XANES spectra. The concentration profiles suggested that the direct photoreduction proceeds in the order of Rh Rh Rh. A reaction mechanism, which was proposed involving photoreductions of Rh and Rh, photoinduced autocatalytic reductions of Rh and Rh, and photooxidation of Rh, well reproduced the concentration profiles of three Rh species.

Proton chelating ligands drive improved chemical separations for rhodium

Narita, Hirokazu*; Nicolson, R. M.*; Motokawa, Ryuhei; Ito, Fumiyuki*; Morisaku, Kazuko*; Goto, Midori*; Tanaka, Mikiya*; Heller, W. T.*; Shiwaku, Hideaki; Yaita, Tsuyoshi; et al.

Inorganic Chemistry, 58(13), p.8720 - 8734, 2019/07

https://doi.org/10.1021/acs.inorgchem.9b01136

Hydroformylation of olefins by a rhodium single-atom catalyst with activity comparable to RhCl(PPh)

Lang, R.*; Li, T.*; Matsumura, Daiju; Miao, S.*; Ren, Y.*; Cui, Y.-T.*; Tan, Y.*; Qiao, B.*; Li, L.*; Wang, A.*; et al.

Angewandte Chemie; International Edition, 55(52), p.16054 - 16058, 2016/12

http://doi.org/10.1002/anie.201607885

In-situ XAFS analysis of Y zeolite-supported Rh catalysts during high-pressure hydrogenation of CO

Bando, Kyoko*; Saito, Takeru; Sato, Koichi*; Tanaka, Tomoaki*; Dumeignil, F.*; Imamura, Motoyasu*; Matsubayashi, Nobuyuki*; Shimada, Hiromichi*

Topics in Catalysis, 18(1-2), p.59 - 65, 2002/01

no abstracts in English

Separation of geometric isomers of metal -diketonates by supercritical fluid chromatography

K.E.Laintz*; Meguro, Yoshihiro; ; Tachikawa, Enzo

J. High Resolut. Chromatogr., 16, p.372 - 375, 1993/06

https://doi.org/10.1002/jhrc.1240160608

no abstracts in English

The draing of noble metals in vitrified nuclear waste by a melter with a sloping floor -Research Report on Solidification of High-Level Liquid waste

; Takahashi, Takeshi

PNC TN8410 91-158, 19 Pages, 1991/04

Joule heated ceramic melter has been developed to vitrify high-level liquid wastes (HLLW) from reprocessing nuclear spent fuel at Power Reacter and Nuclear Fuel Development Corporation (PNC). Noble metal elements such as ruthenium, paladium and rhodium are contained as fission products in the HLLW. The operational chracteristics of Joule-heated ceramic melter were studied on the effects of these elements. Two small scale melters with sloped floor were fabricated and tested. The slope was 30 and 45 for each. The operational characteristics including electrode resistance, temperature profile etc. were monitored. The drain efficiency of noble metal elements from the melters during the glass drain operation were evaluated. After the test operation, the melters were cut after cooled with the glass left in the melting cavities, following the termination of the test operations. The sediments of the precipitations of the noble metal elements were evaluated from the sectional observation for the melter. The results from the studies were compared between 30 and 45 slopes and discussed. It was concluded that the 45 sloped floor was clearly effective to drain the noble metal elements and the structure of the 45 sloped floor melter was compatible with some amount of precipitates at the bottom.

Solvent extraction behavior of rhodium from nitric acid solutions

Morita, Misaki*; Araki, Yuta*; Uehara, Akihiro*; Fukutani, Satoshi*; Tsubata, Yasuhiro; Matsumura, Tatsuro; Fujii, Toshiyuki*

no journal, , 

no abstracts in English

DXAFS study on laser-induced photoreduction mechanism of Rh ion complexes; Extraction of intermediates information by multivariate spectral analysis

Saeki, Morihisa*; Matsumura, Daiju; Nakanishi, Ryuzo*; Yomogida, Takumi; Tsuji, Takuya; Saito, Hiroyuki*; Oba, Hironori*

no journal, , 

The precious metal (PM) ions complexed with negative ions and water molecules in solution has a charge transfer absorption band in the UV region. When alcohol is added to such a PM complex solution and irradiated with an ultraviolet laser, the PM complex is electronically excited and reacts with the alcohol to be reduced to the neutral atom PM. The reduced PM spontaneously aggregates in the solution to form fine particles. This process is called Laser-Induced Particle Formation (LIPF), and is used for the formation of precious metal nanoparticles and the recovery of precious metals from factory effluents. We have investigated the LIPF reaction mechanism of Rh ion complexes by in situ energy-dispersive X-ray absorption fine structure spectroscopy(XAFS). As a result of analyzing the obtained XAFS spectra, we found that Rh species with three oxidation numbers are involved in the Rhreduction reaction, which proceeds from Rh to Rh (intermediate) to Rh.