Direct Single-Enzyme Biomineralization of Catalytically Active Ceria and Ceria–Zirconia Nanocrystals

Journal Article · Tue Feb 21 04:00:00 EST 2017 · ACS Nano

DOI:https://doi.org/10.1021/acsnano.7b00696· OSTI ID:1368336

Curran, Christopher D.; Lu, Li; Jia, Yue; Kiely, Christopher J.; Berger, Bryan W.; McIntosh, Steven

Biomineralization is an intriguing approach to the synthesis of functional inorganic materials for energy applications whereby biological systems are engineered to mineralize inorganic materials and control their structure over multiple length scales under mild reaction conditions. Herein we demonstrate a single-enzyme-mediated biomineralization route to synthesize crystalline, catalytically active, quantum-confined ceria (CeO2–x) and ceria–zirconia (Ce1–yZryO2–x) nanocrystals for application as environmental catalysts. In contrast to typical anthropogenic synthesis routes, the crystalline oxide nanoparticles are formed at room temperature from an otherwise inert aqueous solution without the addition of a precipitant or additional reactant. An engineered form of silicatein, rCeSi, as a single enzyme not only catalyzes the direct biomineralization of the nanocrystalline oxides but also serves as a templating agent to control their morphological structure. The biomineralized nanocrystals of less than 3 nm in diameter are catalytically active toward carbon monoxide oxidation following an oxidative annealing step to remove carbonaceous residue. The introduction of zirconia into the nanocrystals leads to an increase in Ce(III) concentration, associated catalytic activity, and the thermal stability of the nanocrystals.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: NSF
• OSTI ID: 1368336
• Journal Information: ACS Nano, Journal Name: ACS Nano Journal Issue: 3 Vol. 11; ISSN 1936-0851
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CO oxidation
biomineralization
catalysis
ceria
ceria−zirconia
nanoparticle
solid solution