Catalysis
Raspberry-colloid templated (RCT) catalysts
Nanoparticle-supported heterogeneous catalysts play a central role in the production of more than 90% of chemicals manufactured globally. The performance (activity, selectivity, stability) of these catalysts is predicated on a variety of descriptors related to the nanoparticles (NPs), support material, and their interactions. To unequivocally elucidate structure-property relationships to guide future catalyst design, we have drawn (bio)inspiration from the morpho butterfly, in combination with our expertise in colloidal synthesis, assembly, and sol-gel chemistry, to devise raspberry-colloid templated (RCT) catalyst platform (a–e). The RCT strategy is highly modular synthetically, allowing for independent control over the various material building blocks and in their 3D spatial organization at different length scales (from nano- to macroscopic). Most importantly, unlike catalysts prepared using conventional methods, the RCT method derives catalysts with NPs deeply entrenched within the support structure (h), conferring enhanced thermal stability (>500 °C) against NP sintering for a variety of gas- and liquid-phase hydrogenation and oxidation reactions.
Contact: Kang Rui Garrick Lim (garrick_lim@g.harvard.edu)
Publications
2025
The performance of bimetallic dilute alloy catalysts is largely determined by the size of minority metal ensembles on the nanoparticle surface. By analyzing the synthesis of catalysts comprising Pd8Au92 nanoparticles supported on silica using surface...
Au supported on TiO2 is a promising photocatalyst due to its ability to catalyze reactions under illumination and store electrons for sustained reactivity in the dark. Using density functional theory (DFT), we investigate the structural evolution and...
In the one-pot reaction between nitroarenes, aldehydes, and hydrogen, the desired outcome is the selective hydrogenation of nitroarenes to form aminoarenes that condense with aldehydes to yield pharmaceutically relevant imines and N-alkylamines. One...
Most supported catalysts are produced by forming or attaching nanoparticles onto surfaces of supports. However, controlling the interfacial contact between the nanoparticles and support?which has been reported to be the active site for many catalytic...
2024
Conventional catalyst preparative methods commonly entail the impregnation, precipitation, and/or immobilization of nanoparticles on their supports. While convenient, such methods do not readily afford the ability to control collective ensemble-like...
Restructuring of metal components on bimetallic nanoparticle surfaces in response to the changes in reactive environment is a ubiquitous phenomenon whose potential for the design of tunable catalysts is underexplored. The main challenge is the lack of...
Innovative bimetallic nanoparticles are impactful materials for heterogenous catalysis, as the synergy between two metals can be beneficial to increase activity, selectivity, and stability [1, 2]. For instance, it has been shown that Au-Pd nanoparticles...
Gold nanoparticle-loaded titania (Au/TiO) inverse opals are highly ordered three-dimensional photonic structures with enhanced photocatalytic properties. However, fine control over the placement of the Au nanoparticles in the inverse opal structures...
Nanoparticle (NP) size and proximity are two physical descriptors applicable to practically all NP-supported catalysts. However, with conventional catalyst design, independent variation of these descriptors to investigate their individual effects on...
Disentangling the effects of nanoparticle proximity and size on thermal catalytic performance is challenging with traditional synthetic methods. Here we adapt a modular raspberry-colloid-templating approach to tune the average interparticle distance of...
Dilute PdAu alloys are promising catalysts for selective oxidation with high activity and high selectivity. The promotional effect of Pd for selective alcohol oxidation is strongly dependent on the alkyl chain length. Whereas Pd substantially promotes the...
2023
A variety of materials have been developed over the last two decades with the goal of extending the function of light-absorbing devices to low-light or nighttime conditions. Typically, this requires storage of photogenerated charges. The capacity of a...