One-Step Synthesis of Pt-Pd@ACF Catalyst in the Microreactor System for the Hydrogen Evolution Reaction

Currently, new technologies for catalyst synthesis for the production of green energy are being sought. Platinum-based materials are of particular interest due to their unique catalytic properties. In this work, a one-step synthesis of a bimetallic Pt-Pd@ACF (ACF = activated carbon fibers) catalyst in the microreactor system was demonstrated. For this purpose, a glass microreactor was applied, and synthesized catalysts were analyzed using the following techniques: spectrophotometry, TEM, SEM, DLS, XRD, and MP-AES (microwave plasma atomic emission spectroscopy). The obtained results showed that the process of catalyst deposition on ACF as a catalyst carrier is more efficient in the microreactor system compared to the analogous process carried out in a batch reactor. Moreover, the composition of the catalyst can be slightly changed with the flow rate. It contained 32% of Pt and 68% of Pd for a flow rate of 5 mL/min and 33% of Pt and 67% of Pd for the lowest flow rate, i.e., 1 mL/min. While the amount of catalyst deposited on ACF can be adjusted by using the flow rate in the order from the lowest to the highest. The catalytic properties of the catalyst were tested for the hydrogen evolution reaction (HER). The catalytic performance of the synthesized material was directly related to its amount on the carbon surface. The highest catalytic activity was observed for the catalyst synthesized at a flow rate of 5.0 mL/min, and the registered current for HER achieved -25 mA at a potential of -0.28 V.