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Gold‐Silver Catalysts: Ruling Factors for Establishing Synergism
Author(s) -
Stucchi Marta,
Jouve Andrea,
Villa Alberto,
Nagy Gergely,
Németh Miklòs,
Evangelisti Claudio,
Zanella Rodolfo,
Prati Laura
Publication year - 2019
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201900591
Subject(s) - calcination , bimetallic strip , x ray photoelectron spectroscopy , catalysis , thermal treatment , particle size , materials science , chemical engineering , chemical state , particle (ecology) , oxidation state , inorganic chemistry , nuclear chemistry , chemistry , organic chemistry , composite material , oceanography , engineering , geology
DPU and SOL immobilisation have been used to prepare 1 %AuAg/TiO 2 with internal ratio 1 : 1 and 4 : 1 which have been studied as fresh, calcined in air at 300 °C and reduced at 550 °C in H 2 . TEM‐EDS, XPS, UV‐Vis and CO‐DRIFT allowed to characterize the samples in terms of particle size, particle composition, exposure and oxidation state of metals. Correlating these characteristics to the catalytic behaviour we concluded that only Au‐rich catalysts show synergistic effect, silver in bimetallic systems appears more resistant to oxidation than in monometallic one, thermal treatment enhances the SMSI thus producing (regardless to the post‐treatment) almost the same amount of Au δ+ and also Ag δ+ . Catalysts prepared by DPU (calcined in air or reduced in H 2 ) are more active than SOL (fresh or calcined) probably due to the higher presence of gold at the surface.