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New Architectures for Designed Catalysts: Selective Oxidation using AgAu Nanoparticles on Colloid‐Templated Silica
Author(s) -
Shirman Tanya,
Lattimer Judith,
Luneau Mathilde,
Shirman Elijah,
Reece Christian,
Aizenberg Michael,
Madix Robert J.,
Aizenberg Joanna,
Friend Cynthia M.
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201704552
Subject(s) - bimetallic strip , nanoporous , catalysis , materials science , nanoparticle , chemical engineering , colloid , selectivity , porosity , reactivity (psychology) , nanotechnology , nanocrystal , methanol , template , chemistry , organic chemistry , composite material , medicine , alternative medicine , pathology , engineering
A highly modular synthesis of designed catalysts with controlled bimetallic nanoparticle size and composition and a well‐defined structural hierarchy is demonstrated. Exemplary catalysts—bimetallic dilute Ag‐in‐Au nanoparticles partially embedded in a porous SiO 2 matrix (SiO 2 –Ag x Au y )—were synthesized by the decoration of polymeric colloids with the bimetallic nanoparticles followed by assembly into a colloidal crystal backfilled with the matrix precursor and subsequent removal of the polymeric template. This work reports that these new catalyst architectures are significantly better than nanoporous dilute AgAu alloy catalysts (nanoporous Ag 3 Au 97 ) while retaining a clear predictive relationship between their surface reactivity with that of single‐crystal Au surfaces. This paves the way for broadening the range of new catalyst architectures required for translating the designed principles developed under controlled conditions to designed catalysts under operating conditions for highly selective coupling of alcohols to form esters. Excellent catalytic performance of the porous SiO 2 –Ag x Au y structure for selective oxidation of both methanol and ethanol to produce esters with high conversion efficiency, selectivity, and stability was demonstrated, illustrating the ability to translate design principles developed for support‐free materials to the colloid‐templated structures. The synthetic methodology reported is customizable for the design of a wide range of robust catalytic systems inspired by design principles derived from model studies. Fine control over the composition, morphology, size, distribution, and availability of the supported nanoparticles was demonstrated.