Chitosan based reasonably stable membranes were prepared as polymeric electrolyte and separator for enzymatic fuel cell applications. Glucose oxidase (GOx) bioanode centered biofuel cell with the developed chitosan membranes performed much better in stability with high current densities than that of the biofuel cell utilizing a 125 μ‐thick perfluorosulfonic acid‐type membrane (i. e. Nafion® 115). Proposed chitosan membrane structural stability was enhanced by employing cellulosic support materials and chemical crosslinking. The effects of pH, buffer type, buffer concentration, temperature on the manufactured chitosan membranes along with the biofuel cell system were investigated. The biofuel cell operation parameters were optimized for the current density and stability aspects and more than 3 mA cm?2 current density was acquired from the cell at optimum conditions. Operational half‐life of the chitosan membrane was found as higher than the half‐life of the GOx immobilized bioanode. Therefore, this result indicates that chitosan membrane structural stability was not a limiting issue for the biofuel cell lifespan. 相似文献
The development of high efficient stacks is critical for the wide spread application of proton exchange membrane fuel cells (PEMFCs) in transportation and stationary power plant. Currently, the favorable operation conditions of PEMFCs are with single cell voltage between 0.65 and 0.7 V, corresponding to energy efficiency lower than 57%. For the long term, PEMFCs need to be operated at higher voltage to increase the energy efficiency and thus promote the fuel economy for transportation and stationary applications. Herein, PEMFC single cell was investigated to demonstrate its capability to working with voltage and energy efficiency higher than 0.8 V and 65%, respectively. It was demonstrated that the PEMFC encountered a significant performance degradation after the 64 h operation. The cell voltage declined by more than 13% at the current density of 1000 mA cm−2, due to the electrode de-activation. The high operation potential of the cathode leads to the corrosion of carbon support and then causes the detachment of Pt nanoparticles, resulting in significant Pt agglomeration. The catalytic surface area of cathode Pt is thus reduced for oxygen reduction and the cell performance decreased. Therefore, electrochemically stable Pt catalyst is highly desirable for efficient PEMFCs operated under cell voltage higher than 0.8 V. 相似文献
Summary: Poly(2,5‐benzimidazole) (ABPBI) was synthesized in a novel polymerization medium containing CH3SO3H and P2O5. 3,4‐Diaminobenzoic acid, a monomer for ABPBI, is soluble in the medium and the polymerization was therefore performed in a homogeneous state. It produced polymer fibers, thus simplifying the work‐up process. The membrane was cast directly from the polymerization mixture. Proton conductivities of the ABPBI membranes ranged from 0.02 to 0.06 S · cm−1 above 100 °C, without humidification, and the tensile strength of the membrane was approximately 100 MPa.
Synthesis of ABPBI in a medium containing methanesulfonic acid and P2O5. 相似文献
Novel poly(2‐(3‐sulfo)benzoyl‐1,4‐phenylene)‐block‐polynaphthalimide (PSP‐b‐PI) copolymers were successfully synthesized by Ni(0)‐catalyzed copolymerization of 2,5‐dichloro‐3′‐sulfo‐benzophenone and dichloro‐terminated naphthalimide oligomer. The membranes exhibited a microphase‐separated structure and good hydrolytic stability at 130 °C. They showed a fairly strong anisotropy of membrane swelling with much smaller in‐plane swelling, but a rather weak anisotropy of proton conductivity. The membranes had a fairly high through‐plane conductivity in water and even under low relative humidity. The PSP‐b‐PI copolymer with an IEC of 1.5 meq · g−1 showed high PEFC performance due to the high through‐plane conductivity.
