![]() ![]() The Primacs MCS software collects the data and calculates the TOC concentration of the sample by substraction ( TC - IC = TOC). IC is determined by acidification of the sample in the IC reactor. TC is determined by catalytic oxidation and detection by the NDIR detector of the Formacs SERIES TOC analyzer. The Primacs MCS is equipped with a dual-oven design, allowing separate analysis of Total Carbon (TC) and Inorganic Carbon (IC). The Formacs SERIES Total Organic Carbon / Total Nitrogen analyzers can be extended with the Primacs MCS add-on module for Total Organic Carbon (TOC) analysis for solid materials such as soil, sediments and sludges. The instrument has the possibility with a dual needle set-up to acidify and purge the following sample while analyzing the current one, which saves valuable analysis time. Sample pre-treatment for NPOC determination is fully controlled by the operation software and can be set in preferred mode by the operator. The auto-sampler is available with different carrousels for vials with different volumes. For larger sample numbers an optional random access auto-sampler is available for complete automation of the TOC determination. The Total Organic Carbon analyzer can be operated as a stand-alone analyzer where sample and standard solutions are introduced directly through a rotary septumless injection port for analysis of TC and TIC. This design was developed to conform to the latest customer requirements and allows the determination of TOC in clean waters such as pharmaceutical - and drinking waters but also performing equally well for the analysis of waste, surface, seawater and soil extracts. The voltage is significant, Yu said, because while a voltage of at least 1.23 V is required to produce hydrogen, chlorine is produced at a voltage of 1.73 V, meaning the device had to be able to produce meaningful levels of current density with a voltage between the two levels.The Formacs HT Total Organic Carbon high temperature catalytic combustion system features a versatile modular design and excellent performance for the analysis of Total Carbon (TC), Total Inorganic Carbon (TIC), Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC) and Non-Purgeable Organic Carbon (NPOC). ![]() The catalysts were integrated into a two-electrode alkaline electrolyzer, which can be powered by waste heat via a thermoelectric device or by an AA battery.Ĭell voltages required to produce a current density of 100 milliamperes per square centimeter (a measure of current density, or mA cm -2) ranged from 1.564 V to 1.581 V. To address the challenges, the researchers designed and synthesized a three-dimensional core-shell oxygen evolution reaction catalyst using transition metal-nitride, with nanoparticles made of a nickel-iron-nitride compound and nickel-molybdenum-nitride nanorods on porous nickel foam.įirst author Luo Yu, a postdoctoral researcher at UH who is also affiliated with Central China Normal University, said the new oxygen evolution reaction catalyst was paired with a previously reported hydrogen evolution reaction catalyst of nickel-molybdenum-nitride nanorods. "But the availability of clean freshwater is limited." "Most people use clean freshwater to produce hydrogen by water splitting," he said. Anderson Chair Professor of physics at UH, said it also would work with wastewater, providing another source of hydrogen from water that is otherwise unusable without costly treatment. The researchers tested the catalysts with seawater drawn from Galveston Bay off the Texas coast. Chlorine ions are especially problematic, in part because chlorine requires just slightly higher voltage to free than is needed to free hydrogen. Zhifeng Ren, director of the Texas Center for Superconductivity at UH and a corresponding author for the paper, said a major obstacle has been the lack of a catalyst that can effectively split seawater to produce hydrogen without also setting free ions of sodium, chlorine, calcium and other components of seawater, which once freed can settle on the catalyst and render it inactive. The work is described in Nature Communications. ![]() Researchers say the device, composed of inexpensive non-noble metal nitrides, manages to avoid many of the obstacles that have limited earlier attempts to inexpensively produce hydrogen or safe drinking water from seawater. Researchers from the University of Houston have reported a significant breakthrough with a new oxygen evolution reaction catalyst that, combined with a hydrogen evolution reaction catalyst, achieved current densities capable of supporting industrial demands while requiring relatively low voltage to start seawater electrolysis. ![]()
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