Cascade Reactions in Nanozymes: Spatially Separated Active Sites inside Ag-Core−Porous-Cu-Shell Nanoparticles for Multistep Carbon Dioxide Reduction to Higher Organic Molecules

Abstract

Enzymes can perform complex multistep cascade reactions by linking multiple distinct catalytic sites via substrate channeling. We mimic this feature in a generalized approach with an electrocatalytic nanoparticle for the carbon dioxide reduction reaction comprising a Ag core surrounded by a porous Cu shell, providing different active sites in nanoconfined volumes. The architecture of the nanozyme provides the basis for a cascade reaction, which promotes C−C coupling reactions. The first step occurs on the Ag core, and the subsequent steps on the porous copper shell, where a sufficiently high CO concentration due to the nanoconfinement facilitates C−C bond formation. The architecture yields the formation of n-propanol and propionaldehyde at potentials as low as −0.6 V vs RHE. ; W.S. is grateful for financial support by the Deutsche Forschungsgemeinschaft (EXC-2033-390677874) and the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement no. 833408). This work was supported by the DAAD in the framework of the PPP project 57446293 as well as the Ruhr University Research school PLUS through a research stay of P.W. at UNSW, funded by Germany's Excellence Initiative (DFG GSC 98/3). This research was financially supported by the Australian Research Council of Centre of Excellence in Convergent Bio-Nano Science and Technology (CE140100036), the ARC Australian Laureate Fellowship (FL150100060), the Discovery Project (DP190102659), and the Mark Wainwright Analytical Centre (MWAC) at UNSW. This work used the facilities supported by Microscopy Australia at the Electron Microscope Unit at UNSW. The authors are grateful to Dr. Douglas Lawes for discussion and assistance with 1H NMR experiments. P.B.O'M. acknowledges the Australian Government Research Training Program Scholarship for financial support. P.W. is grateful to the Association of the Chemical Industry e.V. (VCI) for funding of the Ph.D. fellowship.