Membrane Reactor Supported by MXene (Ti<sub>3</sub>C<sub>2</sub>T<i><sub>X</sub></i>) for Hydrogen Production by Ammonia Decomposition
Chengliang Wu, Yun Jin, Yiyi Fan, Ngie Hing Wong, Jaka Sunarso, Xiuxia Meng, Naitao Yang
Abstract
Hydrogen (H 2 ) production by ammonia (NH 3 ) decomposition offers a solution to the energy problem. In this work, an MXene (titanium carbide, Ti 3 C 2 T X ) 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 H 2 production by NH 3 decomposition. The MXene membrane reactor could achieve an H 2 permeance of 2.85 × 10 –7 mol m –2 s –1 Pa –1 and an H 2 /N 2 selectivity of 20 at 773.15 K. Next, a Ni-La/γ-Al 2 O 3 catalyst prepared by impregnation and sintering was added to catalyze the NH 3 decomposition process. The experimental results showed that the reactor could achieve a 99% NH 3 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 ( E ad ) of the MXene membrane for H 2 and N 2 permeances were 64.95 and 69.53 kJ mol –1, respectively. The activation energy ( E ar ) of NH 3 decomposition was 147.8 kJ mol –1 . Both the experimental and modeling results showed that the membrane reactor could enhance NH 3 conversion and promote the production of high-purity H 2 .