Standalone micro-reformer for on-demand hydrogen production from dimethyl ether

Abstract

Entering a new era of sustainable energy generation and consumption, micro-fuel cells are showing great potential for providing high energy density to consumer electronics, and micro-reactor technology can indeed enable their integration by providing hydrogen on-demand from hydrocarbons. In this work, we present the design and fully scalable wafer-level fabrication of a MEMS-based catalytic micro-reactor tested in real-life operating conditions by means of a 3D printed ceramic housing. The device consists of an array of thousands of vertically aligned micro-channels, 500 μm in length and 50 μm in diameter, for an overall superficial area per unit volume of 120 cm2 cm−3 and it embeds a thin-film heater for efficient reaction start-up. For the first time, functionalization of the micro-reactor is entirely achieved by atomic layer deposition (ALD) and rapid thermal processing (RTP), resulting in the uniform coating of a Pt/Al2O3 heterogeneous catalyst hereby tested for steam reforming (SR) and partial oxidation (POX) of dimethyl ether (DME). Here, conversion rates up to 74% and hydrogen selectivity of ~60% are obtained by steam reforming at 650 °C, while a specific volumetric hydrogen production of 4.5 mLH2 mL−1DME cm−3REACTOR at 600 °C is obtained from DME POX.