Electronic and reactivity changes in epitaxially grown Ce1-xZrxO2-δ (111) thin films

IF 2.1 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science Pub Date : 2025-03-17 DOI:10.1016/j.susc.2025.122739

Ashutosh Mishra , Allison M. Robinson , Craig L. Perkins , Eric M. Karp , J. Will Medlin

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引用次数: 0

Abstract

Ceria composite catalysts have long been used for ketonization reactions, which is a valuable chemistry for the upgrading of biomass-derived carboxylates. To better understand the interaction of zirconia with ceria in the context of ketonization, thin epitaxial films of ceria-zirconia mixed metal oxide Ce_1-xZr_xO_2-δ (x = 0–1) were grown on a Pt(111) substrate in ultrahigh vacuum conditions and studied with X-ray photoelectron spectroscopy (XPS). Core level and valence band XPS results suggest a strong interaction between ceria and zirconia cations, possibly due to increased filling of unoccupied 4f⁰ orbitals of ceria from neighboring Zr cations in the lattice structure. This leads to a partial reduction of ceria from Ce⁴⁺ to Ce³⁺, with Zr remaining predominantly in the 4+ oxidation state. Ketonization of acetic acid was studied using temperature programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). These results found ketonization over mixed Ce-Zr composite oxides exhibited lower activation energies than for pure CeO₂ and ZrO₂, with Ce_0.38Zr_0.62O_2-δ exhibiting the highest yield of acetone among the studied surfaces. These results suggest the high activity of Ce-Zr catalysts appears to be a result of oxygen vacancy formation, stabilized by electron donation from Zr cations.

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来源期刊

Surface Science 化学-物理：凝聚态物理

CiteScore

3.30

自引率

5.30%

发文量

137

审稿时长

25 days

期刊介绍： Surface Science is devoted to elucidating the fundamental aspects of chemistry and physics occurring at a wide range of surfaces and interfaces and to disseminating this knowledge fast. The journal welcomes a broad spectrum of topics, including but not limited to: • model systems (e.g. in Ultra High Vacuum) under well-controlled reactive conditions • nanoscale science and engineering, including manipulation of matter at the atomic/molecular scale and assembly phenomena • reactivity of surfaces as related to various applied areas including heterogeneous catalysis, chemistry at electrified interfaces, and semiconductors functionalization • phenomena at interfaces relevant to energy storage and conversion, and fuels production and utilization • surface reactivity for environmental protection and pollution remediation • interactions at surfaces of soft matter, including polymers and biomaterials. Both experimental and theoretical work, including modeling, is within the scope of the journal. Work published in Surface Science reaches a wide readership, from chemistry and physics to biology and materials science and engineering, providing an excellent forum for cross-fertilization of ideas and broad dissemination of scientific discoveries.