Palladium catalyzes hydrogen production from formic acid: significant impact of support polypyrrole

Abstract

As a simple and promising hydrogen carrier, hydrogen production from formic acid (HCOOH) has been extensively investigated, owing to the properties of colorlessness, non-toxicity, and safety of formic acid. Palladium-based catalysts are commonly applied in thermocatalysis reactions, hydrogenation reactions as for example. A facile method is used to synthesize Pd/polypyrrole (Pd/PPy) catalysts. The catalytic activity of Pd/PPy from formic acid for hydrogen production was investigated. The support of catalysts were with two different state, one support of PPy was synthesized by chemical in situ polymerization, while the other was purchased. Using a collection of characterizations to determine the structure and morphology properties of as-prepared Pd/PPy catalysts, such as XRD, SEM, TEM, FT-IR, BET and XPS. The as-prepared Pd/PPy catalysts have a good catalytic activity for hydrogen production from formic acid. Meanwhile, Pd/PPy-S1, which support was synthesized by chemical in situ polymerization, has a better catalytic activity for dehydrogenation of formic acid. Apart from the different specific surface area and similar particle size of Pd ranging from 5 nm to 30 nm, the distinctive interaction of Pd and PPy results the different catalytic activity. We finally came up with a proposed possible reaction mechanism. This work provides some significant guidance in high efficiency catalysts development for hydrogen production from formic acid.