(758e) First Detection and Characterization of Super-Electrophilic Metal (Pt+2, Pd+2, Ag+) Cations in Zeolite SSZ-13: Novel Chemistry for Adsorption and Catalysis Applications
AIChE Annual Meeting
2020
2020 Virtual AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Microporous and Mesoporous Materials III: Metal Chemistry
Thursday, November 19, 2020 - 9:00am to 9:15am
We provide the first observation and characterization of super-electrophilic metal cations. To identify and characterize them, we synthesized high loadings (1 wt%) of uniform atomically dispersed Pd+2 cations in a small-pore zeolite SSZ-13 [1,2]. Because of the uniformity and selective formation of the Pd+2//2Al species for this material, we were able to unravel their unique chemistry. Previously, their spectroscopic signatures have been assigned to Pd+3 and Pd+4 species [3,4]. However, herein we show that in fact [Pd+2//2Al] ions form selectively. We demonstrate that these Pd+2ions are super-electrophilic in nature and quantify super-electrophilicity of a metal (ion) for the first time with the aid of high-resolution in-situ XPS studies (combined with FTIR spectroscopy and DFT calculations).
With aid of FTIR and DFT, we unravel the novel chemistry of Pd+2/SSZ-13 and its complexes with CO, NO, C2H4. We also show the first example of comprehensive modeling of a Pd(Pt)/zeolite system including the interaction with the small molecules (CO,NO,ethylene) â these interactions are of great importance for adsorption (e.g., PNA) and catalysis (ethylene transformations) [1,2].
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