Unraveling the mysterious failure of Cu/SAPO-34 selective catalytic reduction catalysts.

ABSTRACT: Commercial Cu/SAPO-34 selective catalytic reduction (SCR) catalysts have experienced unexpected and quite perplexing failure. Understanding the causes at an atomic level is vital for the synthesis of more robust Cu/SAPO-34 catalysts. Here we show, via application of model catalysts with homogeneously dispersed isolated Cu ions, that Cu transformations resulting from low-temperature hydrothermal aging and ambient temperature storage can be semi-quantitatively probed with 2-dimensional pulsed electron paramagnetic resonance. Coupled with kinetics, additional material characterizations and DFT simulations, we propose the following catalyst deactivation steps: (1) detachment of Cu(II) ions from cationic positions in the form of Cu(OH)₂; (2) irreversible hydrolysis of the SAPO-34 fra

SUBMITTER: Wang A 

PROVIDER: S-EPMC6408507 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature