A wet phase inversion process of polyamic acid (PAA) allowed fabrication of a porous membrane of polyimide (PI) with the combination of a low dielectric constant (1.7) and reasonable mechanical properties (Tensile strain: 8.04%, toughness: 3.4 MJ/m³, tensile stress: 39.17 MPa, and young modulus: 1.13 GPa), with further thermal imidization process of PAA. PAA was simply synthesized from purified pyromellitic dianhydride (PMDA) and 4,4-oxydianiline (ODA) in two different reaction solvents such as γ-butyrolactone (GBL) and N-methyl-2-pyrrolidinone (NMP), which produce M_w/PDI of 630,000/1.45 and 280,000/2.0, respectively. The porous PAA membrane was fabricated by the wet phase inversion process based on a solvent/non-solvent system via tailored composition between GBL and NMP. The porosity of PI, indicative of a low electric constant, decreased with increasing concentration of GBL, which was caused by sponge-like formation. However, due to interplay between the low electric constant (structural formation) and the mechanical properties, GBL was employed for further exploration, using toluene and acetone vs. DI-water as a coagulation media. Non-solvents influenced determination of the PAA membrane size and porosity. With this approach, insight into the interplay between dielectric properties and mechanical properties will inform a wide range of potential low-k material applications.

There is currently no theoretical study on the hydrogenation of xylose to xylitol on a catalyst's surface, limiting proper understanding of the reaction mechanisms and the design of effective catalysts. In this study, DFT techniques were used for the first time to investigate the mechanisms of xylose to xylitol conversion on five notable transition metal (TM) surfaces: Ru(0001), Pt(111), Pd(111), Rh(111), and Ni(111). Two transition state (TS) paths were investigated: TS Path A and TS Path B. The TS Path B, which was further subdivided into TS Path B1 and B2, was proposed to be the minimum energy path (MEP) for the reaction process. According to our computational results, the MEP for this reaction begins with the structural rearrangement of cyclic xylose into its acyclic form prior to step-wise hydrogenation. The rate-determining step (RDS) on Ru(0001), Pt(111), Pd(111), and Ni(111) was discovered to be the ring-opening process via C–O bond scission of cyclic xylose. On Rh(111), however, the RDS was found to be the first hydrogenation stage, leading to the hydrogenation intermediate. Furthermore, based on the RDS barrier, our results revealed that the activities of the tested TM surfaces follow the trend: Ru(0001) > Rh(111) ≥ Ni(111) > Pd(111) > Pt(111). This result demonstrates the higher activity of Ru(0001) compared to other surfaces used for xylose hydrogenation. It correlates with experimental trends in relation to Ru(0001) superiority and provides the basis for understanding the theoretical design of economical and more active catalysts for xylitol production.

The application of protonic ceramic electrolysis cells (PCECs) for ammonia (NH₃) synthesis has been evaluated over the past 14 years. While nitrogen (N₂) is the conventional fuel on the cathode side, various fuels such as methane (CH₄), hydrogen (H₂), and steam (H₂O) have been investigated for the oxygen evolution reaction (OER) on the anode side. Because H₂ is predominantly produced through CO₂-emitting methane reforming, H₂O has been the conventional carbon-free option thus far. Although the potential of utilizing H₂O and N₂ as fuels is considerable, studies exploring this specific combination remain limited. PCEC fabrication technologies are being developed extensively, thus necessitating a comprehensive review. Several strategies for electrode fabrication, deposition, and electrolyte design are discussed herein. The progress in electrode development for PCECs has also been delineated. Finally, the existing challenges and prospective outlook of PCEC for NH₃ synthesis are analyzed and discussed. The most significant finding is the lack of past research involving PCEC with H₂O and N₂ as fuel configurations and the diversity of nitrogen reduction reaction catalysts. This review indicates that the maximum NH₃ synthesis rate is 14 × 10⁻⁹ mol cm⁻² s^−1, and the maximum current density for the OER catalyst is 1.241 A cm⁻². Moreover, the pellet electrolyte thickness must be maintained at approximately 0.8–1.5 mm, and the stability of thin-film electrolytes must be improved.

The development of stable and durable hydrogen (H₂) separation technology is essential for the effective use of H₂ energy. Thus, the use of H₂ permeable membranes, made of palladium (Pd), has been extensively studied in the literature. However, Pd has considerable constraints in large-scale applications due to disadvantages such as very high cost and H₂ embrittlement. To address these shortcomings, copper (Cu) and Pd were deposited on Ta to fabricate a composite H₂ permeable membrane. To this end, first, Pd was deposited on a tantalum (Ta) support disk, yielding 7.4 × 10⁻⁸ molH₂ m⁻¹ s⁻¹ Pa^−0.5 of permeability. Second, a Cu–Pd alloy on a Ta support was synthesized via stepwise electroless plating and plasma sputtering to improve the durability of the membrane. The use of Cu is cost-effective compared with Pd, and the appropriate composition of the PdCu alloy is advantageous for long-term H₂ permeation. Despite the lower H₂ permeation of the PdCu/Ta membrane (than the Pd/Ta membrane), about two-fold temporal stability is achieved using the PdCu/Ta composite. The degradation process of the Ta support-based H₂ permeable membrane is examined by SEM. Moreover, thermocatalytic H₂ dissociation mechanisms on Pd and PdCu were investigated and are discussed numerically via a density functional theory study.