RESUMO
Cellulose nanocrystals (CNCs) were isolated from two-agroindustrial wastes: sugarcane bagasse (SCB) and pinewood sawdust (PWS), to analyze their chemical, structural, morphological, and proton conduction properties in dependence of the synthesis parameters. In both sources, the isolated CNCs correspond to the monoclinic phase of cellulose type I and II. For SCB, the smallest CNCs were isolated, in a range of 3-10 nm, with 5 wt.% of NaOH and 60 °C of acid hydrolysis. PWS displayed the smallest sizes at 75 °C and 10 wt.% NaOH (40-110 nm). Membrane characterization suggests that isolated CNCs, between 75 and 90 °C of acid hydrolysis and 10 wt.% NaOH from both SCB and PWS sources, displayed an important increase in the proton conductivity, 1.23(±0.61)×10-5 and 9.26 (±0.24)×10-5 S-m-1, respectively. Thus, with proper synthesis conditions, CNCs can be potentially used as based element to obtain other proton conductor materials to fabricate PEMs.
RESUMO
Structural, compositional, morphological and electrochemical characterization are important to determinate the influence of platinum in the methanol oxidation in alkaline media. These data and analysis support the research article catalytic performance of alloyed PtxPd1-x nanostructures supported on Vulcan XC-72R for the methanol oxidation in alkaline medium [1]. The data here presented included changes in the chemical composition, structure and microstructure. Also, complement data of cyclic voltammograms during activation in alkaline media as well as in presence of 1 M CH3OH to observe CO tolerance and Electrochemical Impedance Spectroscopy measurements at two different overpotentials (0.2 and 0.3 mV) on the onset potential for methanol electro-oxidation are published in this paper. The data can be used as a reference to determinate the effect of added different amounts of Pd to Pt/C catalysts, using an organometallic compounds method and octylamine as stabilizer. The data provided in this article have not been previously published and are available to enable critical or extended analyses.