Stabilization of a nanoporous NiCu dilute alloy catalyst for non-oxidative ethanol dehydrogenation

Abstract

<p> <italic>In situ</italic> and <italic>ex situ</italic> X-ray photoelectron spectroscopy and electron-microscopy reveal that the stability of nanoporous NiCu alloy catalysts for non-oxidative ethanol dehydrogenation improves by generating kinetically trapped Ni²⁺ subsurface states.</p>

Tracing the reactivity of single atom alloys for ethanol dehydrogenation using ab initio simulations

“…[16][17][18][19] As compared to its oxidative counterpart, the NODH reaction is of paramount importance in the chemical industry, with improved process safety and product selectivity, 18 offering higher yield and reduced catalyst deactivation. 20 Our group has studied this reaction to develop novel bimetallic alloys of Cu, Pt and Ni, using an ab initio MKM, focusing on the reactivity of the step sites for the NODH of ethanol. 16,17 Recent experiments by Flytzani-Stephanopoulos and co-workers have explored the reactivity of SAAs for the NODH reaction of ethanol.…”

Regeneration of Active Surface Alloys during Cyclic Oxidation and Reduction: Oxidation of H2 on Pd/Ag(111)

“…A principal question is whether these structural and compositional changes are reversible so that the active catalyst state is maintained on the surface during reaction cycles, a requirement for catalytic function. Specifically, metastable structures of alloys may be the catalytic phase, as illustrated for nanoporous AgAu, , Ni-doped nanoporous Cu, Ni–Au core–shell nanoparticles, dilute Pd/Au nanoparticles, and Ni–In intermetallic nanoparticles . These catalytic studies further illustrate the principle that the active phase can be formed and regenerated under steady-state conditions; however, studies on single-crystal models that demonstrate cyclic generation of metastable active phases are lacking.…”

Ethanol Decomposition and Dehydrogenation for Hydrogen Production: A Review of Heterogeneous Catalysts

“…60 Janvelyan et al conducted a fundamental study combining in situ ambient pressure XPS and ex situ XPS, environmental TEM, and DFT calculations to understand the surface composition, oxidation states, and the activity−stability of CuNi catalysts for the ethanol dehydrogenation reaction. 61 The authors suggested that the catalyst retained in a kinetically trapped metastable position was critical for high ethanol activity and long-term stability. Catalyst pretreatment by hydrogen leads to higher Ni sites on the surface and quick deactivation of the catalyst, and on the contrary a treatment in the presence of oxygen leads to kinetically trapped Ni 2+ sites on the subsurface of the catalyst, which results in high activity and long-term stable performance.…”

“…Catalyst pretreatment by hydrogen leads to higher Ni sites on the surface and quick deactivation of the catalyst, and on the contrary a treatment in the presence of oxygen leads to kinetically trapped Ni 2+ sites on the subsurface of the catalyst, which results in high activity and long-term stable performance. 61 A first principle microkinetics model predicting the nonoxidative dehydrogenation of ethanol reveals the uniqueness of copper in terms of exceptional selectivity for acetaldehyde. 41 The model predicted the stability of CH 3 CH 2 O species on copper surface compared to CH 3 CO species on other metals evaluated, which includes nickel and cobalt, in addition to the precious group metals Au, Ag, Pd, Pt, Rh, Ru, Re.…”

“…Janvelyan et al conducted a fundamental study combining in situ ambient pressure XPS and ex situ XPS, environmental TEM, and DFT calculations to understand the surface composition, oxidation states, and the activity–stability of CuNi catalysts for the ethanol dehydrogenation reaction . The authors suggested that the catalyst retained in a kinetically trapped metastable position was critical for high ethanol activity and long-term stability.…”