TY - CONF A1 - Bayat, Mehmet Emin T1 - Traceable dynamic and gravimetric preparation of trace ammonia in hydrogen gas standards for ISO 14687 N2 - Trace ammonia impurities in hydrogen fuel poison proton-exchange-membrane fuel cells (PEMFC), causing irreversible performance degradation. Accurate quantification of ammonia in so-called Grade D hydrogen fuel is crucial for ensuring PEMFCs long-term operational stability and performance. According to ISO 14687 grade D hydrogen fuel sets a stringent threshold value of just 100 nmol/mol for ammonia impurities. Given the potential of an ammonia-based hydrogen supply chain, reliable quantification of ammonia contamination appears even more relevant. Hydrogen quality assessments for ammonia impurities typically employ techniques such as gas chromatography, cavity-enhanced absorption spectroscopy, or mass spectrometry. These techniques, however, require stable reference gases for calibration and long-term method validation. Typically, gravimetrically produced reference gases are used. However, ammonia poses unique challenges due to its chemical reactivity and stickiness. By applying (ultra )long-path Optical Feedback Cavity Enhanced Absorption Spectroscopy we observed that above a certain amount of ammonia, the gravimetric amount deviates from the analytically determined amount. This discrepancy most likely arises due to strong adsorption of ammonia onto the inner surface of the gas cylinder. Therefore, we investigated the lowest gravimetrically preparable amount of ammonia in hydrogen for which the analytically measured amount of the cylinder remains congruent with the gravimetric amount of substance. We further investigated the applicability of passivated cylinders for trace ammonia gas standards and compared their performance to aluminum alloy cylinders. To confirm reproducibility of our results, we conducted three independent gravimetric preparation campaigns, each employing optimizations, or changes in methodology, at different times. Finally, we investigated whether those gravimetrically prepared trace amounts of ammonia in hydrogen gas standards were long-term-stable. Beyond gravimetrically prepared gas standards, we evaluated how a cutting-edge dynamic dilution system could reliably extend trace-ammonia calibration down to the ISO limit of 100 nmol/mol. For this purpose, we developed an advanced dynamic dilution system capable of a one-in-a-billion dilution ratio, validated for its SI traceability, reproducibility, and operational limits by applying an internal standard. In summary, our results demonstrate that precise dynamic dilution, coupled with concentrated gravimetrically prepared ammonia gas mixture, provides a route to full SI-traceable trace-ammonia reference sample gases. T2 - Gas Analysis Symposium 2026 CY - Paris, France DA - 27.01.2026 KW - Ammonia KW - Hydrogen KW - Gravimetric preparation KW - OF-CEAS KW - ISO 14687 PY - 2026 AN - OPUS4-65620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Correlative physic-chemical analysis of advanced materials and BAM’s green and zero-related advanced materials activities – Benefits and challenges by examples N2 - Following points are presented: - Nanomaterials BAM, as research materials & CRMs, incl pre-standardization, automated analysis & automated synthesis - 2D-materials BAM HEurope ACCORDs approach Green Deal inspired correlative imaging based characterisation for safety profiling of 2D materials - Sample preparation @BAM , inclusion to standards - Thin Films @BAM as Reference Material Candidates, i) mesoporous, ii) HEA - Substitutional,Transition Me oxides as electrocatalysts a project @BAM - Sustainable mechanochemical reaction engineering projects @BAM. T2 - VAMAS Workshop Advanced Materials Challenges and Standardization Needs for a Greener World CY - Rio de Janeiro, Brazil DA - 25.09.2024 KW - Nanomaterials KW - Advanced materials KW - 2D materials KW - Sample preparation KW - Thin films KW - Reference materials KW - Safety KW - Automation PY - 2024 AN - OPUS4-61404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -