Membrane Reactor Supported by MXene (Ti3C2TX) for Hydrogen Production by Ammonia Decomposition

Abstract

Hydrogen (H2) production by ammonia (NH3) decomposition offers a solution to the energy problem. In this work, an MXene (titanium carbide, Ti3C2TX) membrane was successfully synthesized by depositing it onto the anodic aluminum oxide (AAO) substrate using vacuum-assisted filtration. Then, a membrane reactor supported by MXene was developed for H2 production by NH3 decomposition. The MXene membrane reactor could achieve an H2 permeance of 2.85 × 10–7 mol m–2 s–1 Pa–1 and an H2/N2 selectivity of 20 at 773.15 K. Next, a Ni-La/γ-Al2O3 catalyst prepared by impregnation and sintering was added to catalyze the NH3 decomposition process. The experimental results showed that the reactor could achieve a 99% NH3 conversion at 773.15 K, i.e., 9% higher than that of the packed catalytic reactor (without membrane). A mathematical model of the membrane reactor was developed to explain the experimental results. The calculated activation energies (Ead) of the MXene membrane for H2 and N2 permeances were 64.95 and 69.53 kJ mol–1, respectively. The activation energy (Ear) of NH3 decomposition was 147.8 kJ mol–1. Both the experimental and modeling results showed that the membrane reactor could enhance NH3 conversion and promote the production of high-purity H2.