A PEFC THAT UTILIZES A BOROHYDRIDE COMPOUND, USUALLY SODIUM BOROHYDRIDE IN AQUEOUS ALKALINE MEDIUM, DIRECTLY AS A FUEL IS TERMED AS DIRECT BOROHYDRIDE FUEL CELL (DBFC). A DBFC EMPLOYS AN ALKALINE SOLUTION OF SODIUM BOROHYDRIDE (NABH4) AS FUEL AND OXYGEN AS OXIDANT.DBFC HAS SOME ATTRACTIVE FEATURES SUCH AS HIGH OPEN CIRCUIT POTENTIAL, LOW OPERATIONAL TEMPERATURE AND HIGH POWER DENSITY. THE DBFC IS A PROMISING POWER SYSTEM FOR PORTABLE APPLICATIONS.SODIUM BOROHYDRIDE (NABH4) IS A GOOD ALTERNATIVE TO METHANOL AND HYDROGEN AS A FUEL [1].IN THE RECENT YEARS, EXTENSIVE RESEARCH WORK IS BEING CARRIED OUT AND REPORTED ON IMPROVING THE PERFORMANCE OF NANOCATALYSTS FOR BOTH ANODE AND CATHODE OF FUEL CELLS [2, 3]. IN THIS STUDY THE SINGLE CELL PERFORMANCE OF CARBON SUPPORTED NON-PLATINUM ELECTROCATALYST (HYPERMECTMK14) AS CATHODE MATERIAL WAS USED IN ALKALINE ELECTROLYTE BOROHYDRIDE FUEL CELLS AND COMPARED TO THAT OF 10% PT/C (COMMERCIAL). THE STRUCTURAL AND ELECTROCHEMICAL ASPECTS OF THE HYPERMEC TM K14 AND 10% PT/C (COMMERCIAL) ELECTROCATALYSTS WERE FURTHER INVESTIGATED.X-RAY DIFFRACTION (XRD) INDICATES THE PT AND K14 PARTICLES AVERAGE SIZE IS LESSER THAN 20 NM.SCANNING ELECTRON MICROSCOPY (SEM) SHOWS THE SPHERICAL SHAPE OF PT AND K14 PARTICLES AND DISTRIBUTED HOMOGENEOUSLY ACROSS THE SUBSTRATE MATRIX. THE HYPERMECTMK14 CATHODE SHOWED SUPERIOR PERFORMANCE TO THAT OBSERVED USING THE 10% PT/C CATHODE, E.G. POWER DENSITY UP TO 138 MWCM-2 FOR DBFC WITH HYPERMECTMK14 AS CATHODE. CYCLIC VOLTAMMETRY DATA EXHIBIT THE BETTER BOROHYDRIDE TOLERANCE FOR K14 AND ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS) ANALYSES DEMONSTRATED THAT THE CELL WITH K14 NANOCATALYST SHOWED NOT ONLY LOW OHMIC RESISTANCE BUT ALSO SMALL CHARGE AND MASS TRANSFER RESISTANCES. THE DIFFERENCE IN PERFORMANCE CAN BE ATTRIBUTED TO VARIATIONS IN ACTIVITY TOWARDS OXYGEN REDUCTION REACTION AND IN BOROHYDRIDE TOLERANCE AMONG THE CATHODES.

IN THE RECENT YEARS, EXTENSIVE RESEARCH WORK IS BEING CARRIED OUT AND REPORTED ON IMPROVING THE PERFORMANCE OF NANOCATALYSTS FOR BOTH ANODE AND CATHODE OF POLYMER ELECTROLYTE MEMBRANE FUEL CELL. THE SINGLE CELL PERFORMANCE OF CARBON SUPPORTED NON-PLATINUM ELECTROCATALYST (HYPERMECTMK14) AS CATHODE MATERIAL WAS USED IN ALKALINE ELECTROLYTE BOROHYDRIDE FUEL CELLS AND COMPARED TO THAT OF 10% PT/C (COMMERCIAL). THE STRUCTURAL AND ELECTROCHEMICAL ASPECTS OF THE HYPERMECTM K14 AND 10% PT/C (COMMERCIAL) ELECTROCATALYSTS WERE FURTHER INVESTIGATED. XRAY DIFFRACTION (XRD) INDICATES THE PT AND K14 PARTICLES AVERAGE SIZE. THEIR MORPHOLOGY WAS ANALYZED BY SEM. THE HYPERMECTMK14 CATHODE SHOWED SUPERIOR PERFORMANCE TO THAT OBSERVED USING THE 10% PT/C CATHODE, E.G. POWER DENSITY OF K14 IS UP TO 138 MWCM-2. CYCLIC VOLTAMMETRY DATA EXHIBIT THE BETTER BOROHYDRIDE TOLERANCE FOR K14. SO THE DIFFERENCE IN PERFORMANCE CAN BE ATTRIBUTED TO VARIATIONS IN ACTIVITY TOWARDS OXYGEN REDUCTION REACTION AND IN BOROHYDRIDE TOLERANCE AMONG THE CATHODES.

WITH AN INCREASING DEMAND OF POLLUTION FREE AND CHEAP ENERGY, INVESTIGATORS ARE FOCUSING ON MORE EASILY AVAILABLE, LESS TOXIC AND SAFER FUEL AND THIS BRING THE INVESTIGATOR TO THE VERY ENLIGHTENING CONCEPT OF FUEL CELL WHICH COULD RUN ON GLUCOSE. STUDIES ON ELECTRO-CATALYTIC OXIDATION OF GLUCOSE ARE OF HIGH INTEREST TO THE FUEL CELL COMMUNITY FOR VARIOUS REASONS. GLUCOSE IS EASILY AVAILABLE, CHEAP AND NON-TOXIC BIO-FUEL. NO STORING PROBLEM OR EXPLOSION HAZARD IS ASSOCIATED LIKE HYDROGEN IN HYDROGEN-OXYGEN FUEL CELL. THE STUDIES THROUGHOUT THE LAST FEW DECADES ON ELECTRO-OXIDATION OF SUGARS WAS PERFORMED AND SHOWED THAT NOBLE METAL CATALYST BASED ON PLATINUM AND GOLD IN ALKALINE MEDIA IMPROVE THE RATE OF ELECTRO-OXIDATION OF GLUCOSE RATHER THAN ACIDIC AND NEUTRAL [7-1]. IN THIS WORK PREPARATION OF PLATINUM (PT) ELECTRO CATALYST WAS PERFORMED BY ELECTRODEPOSITING OF PLATINUM ON MODIFIED CARBON PAPER ELECTRODE. THESE ELECTRO CATALYSTS APPLIED FOR STUDY OF ELECTRO-OXIDATION OF GLUCOSE IN ALKALINE MEDIA. SUBSTRATE IS FABRICATED BY DEPOSITION OF 3MG/CM2 CARBON VULCAN PASTE ON CARBON PAPER SHEET THEN IT DRIED BY HEATING IN 200OC FOR 45 MINUTES. AS-PREPARED SUBSTRATE EXPOSE TO PRECURSOR SOLUTIONS INCLUDED OF: 1- H2SO4 (0.5 M) WITH H2PTCL6 (2MM) (MERCK, GERMANY) AND 2- H3PO4 (0.5 M) WITH H2PTCL6 (2MM). THEN 50 CYCLIC VOLTAMMETRY (CV) SCANS (100 MV/S, 1.20 TO − 0.60 V VS. AG/AGCL SAT KCL) WERE APPLIED. THE ONSET OXIDATION POTENTIAL FOR GLUCOSE ELECTRO OXIDATION AT THE PT/C ELECTRO CATALYST (-0.85 V) IS SIMILAR IN THE TWO ELECTRO CATALYSTS AS SHOWN IN FIG1. ON THE OTHER HAND, THE PEAK CURRENT DENSITY OF GLUCOSE ELECTRO OXIDATION AT PLATINUM ELECTRO CATALYST THAT WAS PREPARED IN PHOSPHATE PRECURSOR SOLUTION (23 MA /CM2) IS ABOUT 1.64 TIMES OF THAT AT THE PT ELECTRO CATALYST THAT WAS PREPARED IN SULPHATE PRECURSOR SOLUTION (14 MA /CM2) AT -0.3 V VS AG/CL SAT KCL REFERENCE ELECTRODE

PLATINUM (IV) PRO-DRUGS ARE AN IMPORTANT CLASS OF MOLECULES THAT MIGHT IMPROVE THE PHARMACOLOGICAL PROPERTIES OF THE PLATINUM (II) ANTICANCER AGENTS THAT ARE CURRENTLY USED IN THE CLINIC [1-2]; THEREFORE MANY RESEARCHERS HAVE BEEN DONE TO STUDY THE MECHANISM OF REDUCTION OF PT (IV) TO PT (II). IN THIS RESEARCH, WITH THE AID OF DENSITY FUNCTIONAL THEORY, WE HAVE STUDIED THE MECHANISM OF REDUCTION OF PT)IV) TO PT)II) BY ASCORBIC ACID. FROM OUR CALCULATIONAL RESULTS, IT HAS BEEN REVEALED THAT IN ORDER FOR THE PT (IV) TO BE REDUCED TO PT (II), A PROTON ABSTRACTION SHOULD BE OCCURRED FROM THE ASCORBATE (ASC-) WHICH IS CONNECTED TO THE PT (IV). THERE IS TWO POSSIBILITY FOR THIS PROTON ABSTRACTION; THE FIRST BY ASC- AND THE SECOND BY H2O. OUR CALCULATIONAL RESULTS DEMONSTRATED THAT THIS PROTON ABSTRACTION BY ASC- (TS1) IS KINETICALLY MORE FAVORED THAN H2O (TS2).

NANOPARTICLES WHOSE PROPERTIES DEPEND ON THEIR SIZE ARE, IN PURELY SCIENTIFIC TERMS, FASCINATING.LARGE (>4 NM) METAL ONES HAVE PROPERTIES LIKE THOSE OF BULK METALS, WHEREAS SMALL ONES EXHIBIT MOLECULE-LIKE PROPERTIES SUCH AS HOMO-LUMO GAPS. IN BETWEEN, ONE FINDS QUANTIZED CAPACITORS. SIZE DEPENDENT ELECTROCHEMICAL BEHAVIOR OF NANOCLUSTERS HAS BEEN INVESTIGATED BY VOLTAMMETRY AT NANOSCALE. DUE TO THE HIGH SENSITIVITY OF DIFFERENTIAL PULSE VOLTAMMETRY (DPV) TO DETECT VERY SMALL FARADAIC CURRENT, THIS TECHNIQUE IS CONSIDERED AS A METHOD OF CHOICE IN THIS RESEARCH. IN THIS REGIME OF NANOPARTICLE VOLTAMMETRY, THE MPCS BEHAVE AS QUANTUM CAPACITORS. IT MEANS THAT THE MPCS BEHAVE AS MULTIVALENT REDOX SPECIES DURING CHARGE TRANSFER AT NANOSCALE AS THE INJECTION OF CHARGE TO THE CORES IS QUANTIZED. BECAUSE THE QUANTIZED CHARGING CURRENTS OF THE CLUSTERS ARE DIFFUSION CONTROLLED, THEIR VOLTAMMETRIC BEHAVIOR IS PROPORTIONAL WITH THEIR SIZE.CV/DPV ELECTROCHEMICAL CHARACTERIZATION OF FRACTIONATED NANOCLUSTERS APPROVES OBSERVATION OF QUANTIZED DOUBLE LAYER (QDL) PHENOMENA WHICH IS DETECTED AS A FINGERPRINT ON THE SIZE OF AS PREPARED NANO CLUSTERS. LONG-TERM STABILITY OF NANOCLUSTERS HAS BEEN CHECKED AFTER EVEN ONE YEAR AT ROOM TEMPERATURE. CHEMICALLY SYNTHESIZED PLATINUM NANOCLUSTER IS FRACTIONATED IN A DISPERSANT AND THEN THE SOLID PHASE REPEATEDLY SEPARATED. VOLTAMMETRY BEHAVIOUR OF FINALIZED DISPERSION SERIOUSLY CAN BE ATTRIBUTED TO THE SIZE OF GENERATED NANOCLUSTERS. QUANTIZED CAPACITANCE CHARGING OF PT NANOCLUSTERS SO CALLED MONOLAYER PROTECTED CLUSTERS (MPC) HAS BEEN FREQUENTLY OBSERVED WHICH CONFIRMS THE NANOMETRIC SIZE OF AS-PREPARED NANO CLUSTERS. THE EQUALLY SPACED PEAKS IN CV AND DPV ARISE FROM SUCCESSIVE, QUANTIZED (SINGLE-ELECTRON) CAPACITATIVE CHARGING OF ENSEMBLES OF INDIVIDUAL CLUSTER CORES (I.E., ELECTROCHEMICAL ENSEMBLE COULOMB STAIRCASE CHARGING). THE FINAL APPLICATION OF THIS ULTRAFINE GRAINED NANOSTRUCTURED MATERIAL IS IN CATALYSIS, ENERGY STORAGE AND CONVERSION.