A Review of the Recent Advances in Composite Membranes for Hydrogen Generation Technologies

Abstract

Keeping global warming at 2 degrees and below as stated in the "Paris Climate Agreement" and minimizing emissions can only be achieved by establishing a hydrogen (H₂) ecosystem. Therefore, H₂ technologies stand out in terms of accomplishing zero net emissions. Although H₂ is the most abundant element in the known universe, molecular H₂ is very rare in nature and must be produced. In H₂ production, reforming natural gas and renewable hydrogen processes using electrolyzers comes to the fore. The key to all these technologies is to enhance production speed, performance, and system lifetime. At this point, composite membranes used in both processes come to the fore. This review article summarizes composite membrane technologies used in methane, ethanol, and biomass steam reforming processes, proton exchange membranes, alkaline water electrolysis, and hybrid sulfur cycle. In addition to these common H₂ production technologies at large quantities, the innovative systems developed with solar energy integration for H₂ generation were linked to composite membrane utilization. This study aimed to draw attention to the importance of composite membranes in H₂ production. It aims to prepare a guiding summary for those working on membranes by combining the latest and cutting-edge studies on this subject.

Figure 1

Main H₂ production processes that involve composite membranes; from reforming processes to renewable H₂ production (reproduced with permission from refs (−23), Copyright 2021 MDPI, Copyright 2023 American Chemical Society, Copyright 2017 Elsevier B.V.).

Figure 2

Schematic illustration of (a) a PEM electrolyzer (Reprinted with permission from ref (87) Copyright 2023 IOP Science), (b) composites of polydopamine and Nafion-212 membranes (reproduced with permission from ref (90), Copyright 2022 American Chemical Society), (c) comparative ion exchange capacity (IEC) and proton conductivity values between SPEEK and composite membranes depending on weight percentages of MXene-Cu₂O additives (reprinted with permission from ref (88), Copyright 2023 Elsevier B.V.).

Figure 3

(a) Schematic representation for an AWE cell and composite membrane production steps (reproduced with permission from ref (103), Copyright 2024 John Wiley and Sons.), Zirconia/Polysulfone composite membrane with cellulose nanocrystals; (reprinted with permission from ref (101), Copyright 2021 Elsevieer B.V.), (b) cross-sectional SEM image, (c) cell performance of alkaline cells with 10 wt % KOH, (d) the preparation process of MEA based on PTFE/LDH composite membranes by pore-filling method, (e) and schematic illustration of the designed AWE (reprinted with permission from ref (104), Copyright 2021 Elsevier B.V.).

Figure 4

(a) Schematically illustrated NH₃ decomposition and H₂ permeation in the MXene-based composite membrane reactor (reprinted with permission from ref (135), Copyright 2023 American Chemical Society), (b) NH₃ permeance and selectivity at 50 (left) and 200 °C (right) as a function of metal affinity of bare and metal-doped BTPA membranes prepared by W.-W. Yan et al. (reprinted with permission from ref (139), Copyright 2023 Elsevier B.V.)

Figure 5

(a) Schematic of the preparation of samples with different composites (reprinted with permission from ref (157), Copyright 2023 Elsevier B.V.), (b) schematic diagram of the charge carrier transfer of ZnSe/C/TiO₂ NTAs under light irradiation (reprinted with permission from ref (158), Copyright 2020 Elsevier B.V.).