# Synthesis of Pellet-Based Pd/C Egg-Shell Catalysts for Reversible Hydrogen Storage in Formate/Bicarbonate

## TL;DR

This paper describes a safe and efficient method to create pellet-based catalysts for reversible hydrogen storage using formate and bicarbonate.

## Contribution

A scalable synthesis method for egg-shell Pd/C pellet catalysts with high hydrogen release rates and reusability.

## Key findings

- The catalyst achieves hydrogen release rates up to 17.4 L h–1 and 80 L of CO-free H2.
- The catalyst offers TON/TOF values comparable to advanced powder systems but with easier handling as pellets.
- Reactivation strategies are proposed to enhance catalyst stability during repeated use.

## Abstract

We report the scalable synthesis of egg-shell Pd/C pellet
catalysts
for the reversible formate/bicarbonate hydrogen-storage cycle. This
system is inherently safe, nontoxic and allows for the easy control
of hydrogen storage and release through pressure or temperature. A
simple synthesis protocol with oxalic acid as a chelating additive
furnishes a uniform and thin Pd shell. The optimized catalyst is active
in both half-reactions, delivering hydrogen release rates up to 17.4
L h–1 and 80 L of CO-free H2 and TON/TOF
values comparable to state-of-the-art powder systems while providing
the handling advantages of pellets. Insights into catalyst reactivation
strategies are provided to improve the stability of the optimal material
during repeated use.