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The advancement of technologies for producing chemicals and materials from non-fossil resources is of critical importance. An illustrative example is the dehydrogenation of glucose, to yield gluconic acid, a specialty chemical. In this study, we propose an innovative production route for gluconic acid while generating H2 as a co-product. Our concept involves a dual-function membrane, serving both as a catalyst for glucose dehydrogenation into gluconic acid and as a means to efficiently remove the produced H2 from the reaction mixture. To achieve this two membranes were developed, one catalytically active and one dense aimed at H2 removal. The catalytic membrane showed significant activity, yielding 16% gluconic acid (t=120 min) with a catalyst selectivity of 93% and stable performance over five consecutive cycles. Incorporating the H2 separating membrane showed the significance of H2 removal in driving the reaction forward. Its inclusion led to a twofold increase in gluconic acid yield, aligning with Le Chatelier's principles. As a future prospect the two layers can be combined into a dual-layer membrane which opens the way for a new production route to simultaneously produce gluconic acid and H2, using high-throughput reactors such as hollow-fiber systems.

Hydrogen has gained renewed and growing interest around the world in the recent decades as a high-quality and renewable energy carrier, owing primarily to advances in fuel cells as well as growing environmental concerns. Steam reforming of fossil-based resources is currently the main route to H2 production. The downside of this process, however, is generation of massive amounts of greenhouse gases including CO2 as the byproduct which in turn must be captured to fully exploit the potential of H2. Membrane separation technology has seen significant growth, breakthroughs, and advancements over the last few decades and could be the key component in achieving inexpensive and highly pure H2. However, only a few numbers of membrane materials can withstand the harsh conditions of H2 production through steam reforming. Polybenzimidazole (PBI)-based membranes show excellent chemical, thermal, and mechanical stabilities as well as high intrinsic H2/CO2 selectivity. The objective of this review is to overview the recent development of structurally modified, cross-linked, mixed matrix, and hollow fiber membranes based on PBI for the development of industrially applicable H2-selective membranes.

Water recycling is one of the most sustainable solutions to growing water scarcity challenges. However, wastewaters usually contain organic pollutants and often are at extreme pH, which complicates the treatment of these streams with conventional membranes. In this work, we report the synthesis of a robust membrane material that can withstand prolonged exposure to extreme pH (of 1 or 13 for 2 months). Polyamine thin film composite (TFC) membranes are prepared in situ by interfacial polymerization between 1,3,5-tris(bromomethyl)benzene (tBrMeB) and p-phenylenediamine (PPD). Contrary to conventional polyamide TFC membranes, enhanced pH stability is achieved by eliminating the carbonyl groups from the polymer network. The membranes showed pure water permeance and molecular weight cutoff (MWCO) of 0.28 ± 0.09 L m-2 h-2 bar-1 and 820 ± 132 g mol-1, respectively. The membrane performance is further enhanced by manipulating the monomer structures and replacing p-phenylenediamine with m-phenylenediamine, resulting in a higher permeance of 1.3 ± 0.3 L m-2 h-1 bar-1 and a lower MWCO of 566 ± 43 g mol-1. Given the ease of fabrication and excellent stability, this chemistry represents a step forward in the fabrication of robust membranes for industrial wastewater recycling.