Proceedings of MATSUS23 & Sustainable Technology Forum València (STECH23) (MATSUS23)
Publication date: 22nd December 2022
Well-defined nanocrystals (NCs) serve as outstanding model systems in catalysis thanks to their high degree of tunability with respect to composition, element configuration, size and shape.1 For instance, well-defined copper NCs helped understand the relationship between the morphology and the selectivity of the catalysts toward carbon dioxide electroreduction.1 Moving beyond copper, Cu-based bimetallic NCs become of interest to further elucidate composition-dependent selectivity for this reaction.1 However, a knowledge gap in the chemistry behind the formation of this class of materials exists, thus the tunability of Cu-based bimetallic NCs is quite limited, especially if we focus on Cu-M where M is a transition metal. The synthetic challenge is to find conditions which enable both metals to be simultaneously reduced while avoiding homogeneous nucleation and oxide formation. To tackle this problem, we focus on Cu-Co and Cu-Ni NCs as representative examples of miscibile and immiscible composition, respectively, based on bulk phase diagrams.
In particular, we synthesize well-defined Cu-Co and Cu-Ni NCs while particularly focusing on how reaction intermediates govern the morphologies and the configuration of final products. We adopted a previously suggested synthetic method, based on the use of hexadecanediol, and scrutinized the physicochemical properties of the reaction intermediates proposed as a key species to derive the well-defined product.5,6 Based on the understanding about reaction intermediates, we achieved a high degree of controllability in terms of morphology and configuration of these NCs. We hope our findings pave a road for future studies about Cu-M NCs which are relevant for the carbon dioxide electroreduction.