Hyphenated elemental analysis methods for characterizing trace gas compounds and nano-objects for energy and environmental applications

This thesis addresses two urgent challenges in the pursuit of cleaner energy and environmental sustainability. First, it advances the quantification of problematic trace compounds in biogas derived from waste streams. Second, it refines rapid characterization techniques for nanoparticles (NPs), which play pivotal roles in catalysis and energy storage.

Biogas often contains siloxanes and sulfur compounds that corrode equipment and poison catalysts, impeding widespread adoption of biogas. To overcome this problem, suitable analytical methods are lacking. Here an innovative analytical method is presented, in which a liquid quench sampling system (LQ) is paired with gas chromatographyâ inductively coupled plasma mass spectrometry (GC-ICP-MS). This setup achieves up to 1500-fold preconcentration, enabling sensitive, single-run measurement of siloxanes and sulfur species. Using liquid standards, rather than gaseous ones, reduces calibration errors. Tests demonstrate stable sample storage for at least four weeks, along with high capture efficiencies. Smaller biogas facilities thus benefit from the ability to collect samples onsite and send them elsewhere for analysis without losing analytes. Though the technique excludes extremely volatile compounds (e.g., H2S) and targets known contaminants, it significantly expands analytical capabilities for biogas quality control.

On the nanomaterials front, the thesis further develops the scanning mobility particle sizer-ICP-MS (SMPS-ICP-MS) platform for high-throughput NP analysis. Traditional electron microscopy, although indispensable for nanoscale imaging, is time-consuming and limited in statistical coverage. By classifying aerosolized particles by their electrical mobility and simultaneously measuring elemental composition, SMPS-ICP-MS quickly yields both size distributions and compositional data. Correcting for shape factors enables accurate characterization of anisotropic NPs. Case studies on CuAg catalysts for electrochemical CO2 reduction and CoNiSn(OH)6 for the oxygen evolution reaction show results consistent with microscopy and bulk analyses, at much higher throughput. However, constraints include the need for aqueous suspensions and argon plasma, which may restrict certain sample types.

Collectively, these innovations underscore the value of refined analytical techniques in driving sustainable solutions. The LQ-GC-ICP-MS method supports more reliable biogas upgrading, minimizing damage to equipment, and enabling broader adoption of biomethane. Meanwhile, SMPS-ICP-MS accelerates nanomaterial development, reducing experimental bottlenecks and aiding the design of next-generation catalysts. By enhancing accuracy, simplicity, and throughput in both domains, this thesis paves the way for cleaner, more efficient energy processes and advanced materials. Ultimately, the thesis demonstrates how purposeful integration of sampling systems, separation strategies, and elemental detection fosters more sustainab