Ultimate control over nanoparticle structure, composition, size, and location in supported bimetallic catalysts

Climate change and limitation in resources are the defining issues nowadays. The necessity to adapt in an efficient, economic, and sustainable way becomes urgent. To meet the needs of the growing population while facing the current energy and geopolitical crisis, catalysis remains one of the solutions as it can lower the energy cost to carry out chemical transformations. However, it is equally important to find sustainable and environmentally friendly approaches to the catalyst synthesis. In the meantime, it is essential to keep an ultimate control over the structure, composition and location of the catalyst in the support. We propose supramolecular approaches involving the use of molecular machines to prepare bimetallic catalyst systems for hydrogenation application. We introduce spiropyran as a smart ligand capable of modifying locally the nanoparticles environment with its photoswitch and photoacid properties. Two goals are targeted, the controlled preparation of bimetallic nanoparticles at the atomic scale and the engineering of a tailored protective shell to prevent the catalyst from sintering. Such molecules can be operated by light as a manipulated tool. Light as an external stimulus is advantageous, since it can be delivered with high spatiotemporal precision in a waste free system. Furthermore, the project focuses on the preparation of Pd/Ni bimetallic catalysts with a core-shell geometry. Besides the synergetic aspect enhance by the fine core-shell design affecting its catalytic performance, it permits as well the substitution of rare and costly elements for abundant and accessible transition metals. Therefore, our final goal is to use our developed strategies to prepare Pd@Ni catalysts in a core-shell geometry to economize of expensive Pd at the core and decorate these bimetallic nanoparticles with a silica protective shell.