Advances and challenges of methanol-tolerant oxygen reduction reaction electrocatalysts for the direct methanol fuel cell

Methanol cross-over effects from the anode to the cathode are important parameters for reducing catalytic performance in direct methanol fuel cells.A promising candidate catalyst for the cathode in direct methanol fuel cells must have excellent activity toward oxygen reduction reaction and resistance to methanol oxidation reaction.This review focuses on the methanol tolerant noble metal-based electrocatalysts,including platinum and palladium-based alloys,noble metal–carbon based composites,transition metal-based catalysts,carbon-based metal catalysts,and metal-free catalysts.The understanding of the correlation between the activity and the synthesis method,electrolyte environment and stability issues are highlighted.For the transition metal-based catalyst,their activity,stability and methanol tolerance in direct methanol fuel cells and comparisons with those of platinum are particularly discussed.Finally,strategies to enhance the methanol tolerance and hinder the generation of mixed potential in direct methanol fuel cells are also presented.This review provides a perspective for future developments for the scientist in selecting suitable methanol tolerate catalyst for oxygen reduction reaction and designing high-performance practical direct methanol fuel cells.

Studies on Reduced Extent Method for Inhibited Thermokinetics Of Enzyme－Catalyzed Reaction──Inhibition of the laccase－catalyzed oxidation of o－dihydroxybenzene by m－dihydroxybenzene

The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculating kinetic parameters, KM,Ki and Urn were suggested. This theory was applied to inverstigate the inhibited thermokinetics of laccase-catalyzed oxidation of o-dihydroxybenzene by m-dihydroxybenzene. The experimental results show the inhibition belongs to reversible competitive type, KM=6.224×10-3 mol L-1, Ki=2. 363 × 10-2 mol. L-1.

Revealing the scientific connotation of compatibility of Chinese medicine medica based on self-assembly technology

Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the modernization of TCM. Self-assembly is the combination of active ingredients into aggregates through noncovalent bonds, such as hydrogen bonding, electrostatic interactions, ionic interactions, and hydrophobic interactions. The complex properties and special structures of CMM components create the basis for selfassembly. The self-assembled materials formed after CMM compatibility is an important part of the material basis for the efficacy of TCM, which can help explain the scientific connotations of CMM compatibility. This review summarizes the self-assembly phenomenon from the perspective of drug pair combinations in recent decades and explains the scientific connotation of CMM compatibility about the material basis, pharmacodynamic changes, and mechanism of action, providing new ideas and methods for the study of TCM.