High-Throughput Synthesis And Catalytic Performance Of Noble Metal Nanocatalysts

The performance of catalysts is influenced by a variety of factors,and the need for high-throughput synthesis technology is increasing as extensive experimental validation is often required to determine a specific catalyst formulation.With the development of mechanical automation,the use of high-throughput synthesis platforms will enhance the efficiency and safety of experimental research.Therefore,it is of strong practical importance to construct a practical high-throughput synthesis platform for catalysts and adapt it to the synthesis process in a laboratory environment.The research of this thesis is as follows.（1）A catalyst high-throughput synthesis platform was developed with the goal of high-throughput synthesis of noble metal nanocatalysts.A serial communication was established between the hardware system and the monitoring and control software.The automated high-throughput synthesis of catalysts is controlled based on catalyst formulations.The platform is equipped with auxiliary functions such as ant colony algorithm path optimization,data processing,and database calling.It has the advantages of high accuracy,high reliability,friendly human-computer interaction and reasonable economy,which significantly improves the efficiency of laboratory catalyst synthesis and related research.（2）High-throughput synthesis of silver-based nanocatalysts was achieved by a simple impregnation strategy based on the catalyst high-throughput synthesis platform.The platform repeatability was first verified by synthesizing catalysts of the same formulation.The reaction rate constants of p-nitrophenol hydrogenation experiments revealed small differences between parallel samples.The analysis of results such as inductively coupled plasma emission spectroscopy and transmission electron microscopy further indicated well stability of the platform.In addition,a comparison experiment between manual and automated synthesis was carried out by adjusting the concentration of the impregnating solution to change the silver atom loading.The difference in the reaction rate constants between the two catalysts in the p-nitrophenol hydrogenation experiments was less than 0.1min^-1,and thus the high-throughput synthesis exhibited a good agreement with the manual synthesis.（3）Size tuning of Pt-based nanocatalysts based on a high-throughput synthesis platform,which was achieved by employing glucose as an adjuvant for the modification of the degree of carrier carbonation.The experimental results of the performance evaluation of the catalysts synthesized by this method for p-nitrophenol hydrogenation showed a volcano-type variation when the platinum loading was 1 wt%and 0.5 wt%.The best performance was obtained for the catalyst with 0.2 g of glucose per gram of carrier carbonization.Combining the particle size and X-ray photoelectron spectroscopy analysis,there is a linear inverse relationship between this reaction rate constant and the average particle size of Pt nanoparticles.The higher binding energy at Pt 4d_5/2is favorable for the catalytic effect,in that the carrier is moderately carbonized to cause Pt to lose electrons and increase the valence state,thus controlling the particle size of Pt nanoparticles and enhancing the catalytic performance.（4）Component modulation and screening of Pt-Ag bimetallic nanocatalysts were realized by the high-throughput synthesis platform.A batch of Pt-Ag/γ-Al₂O₃with different Pt and Ag ratios was synthesized by high-throughput and artificial synthesis.The two control samples were in good agreement in the p-nitrophenol hydrogenation experiments,and the performance was optimal when the Pt and Ag mass ratio was 6:4.Combined with X-ray photoelectron spectroscopy and other analyses,it reveals that the introduction of Pt atoms can induce the electron shift of pure Ag catalysts,which means that Ag atoms lose electrons and increase their chemical valence,making it easier to adsorb the anions in the reaction,thus accelerating the catalytic reaction rate.It proves that the high-throughput platform has high credibility and important value in exploratory synthesis experiments.