Study Explores Impact of Getter Substrates on Hydrogenation ...

A recent study conducted by researchers at the Los Alamos National Laboratory in New Mexico, USA, has investigated the impact of different getter substrates on the hydrogenation process using two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC–TOF-MS). The study, published in the Journal of Chromatography A, evaluated the presence of volatiles in the headspace of various DEB/Pd(dba)2 getter substrates, including a getter-infused silicone foam, a hydrogenated getter-infused silicone foam, an activated carbon getter pellet, and a hydrogenated activated carbon getter pellet (1).

A getter substance is a material that is used to absorb or trap unwanted gas molecules in a system. It is commonly used in vacuum systems or electronic devices to eliminate trace gases that could interfere with the device's operation or cause damage. Getter substances can be made of metals or organic compounds, such as acetylene-based compounds like 1,4-bis(phenylethynyl)benzene (DEB) or diphenyl butadiyne (DPB), which are popular hydrogen getters. When a getter substance is exposed to gases, it undergoes a chemical reaction that results in the adsorption or absorption of the unwanted gas molecules.

GC×GC–TOF-MS is a powerful analytical technique used for the separation and identification of complex mixtures of compounds. It combines two-dimensional gas chromatography (GC×GC) with time-of-flight mass spectrometry (TOF-MS) to provide high-resolution separation and detection capabilities. The technique involves the use of two columns with different selectivities, allowing for better separation of complex mixtures. TOF-MS provides accurate mass measurement, allowing for the identification of unknown compounds.

The study showed that the breakdown of materials used in the hydrogenation process can generate unwanted volatiles that can interact with sensitive materials, leading to their deterioration. Therefore, understanding the impact of different substrates on the getter and catalyst degradation is crucial. The study utilized Fisher ratio (F-ratio) analyses to identify compounds generated or consumed during the hydrogenation process.

The study found that different substrates can alter the decomposition products created during the degradation of DEB and Pd(dba)2. The activated carbon pellets produced benzene derivatives such as bibenzyl, benzaldehyde, and vinyl benzoate, as well as alkane/alkene derivatives such as undecane, 4-tridecene, and decane. On the other hand, the silicone foams produced 1,5-diphenyl-3-pentanone, toluene, styrene, 1–1′(2-pentene 1,5-diyl)bis benzene, and 2,6-dimethyl undecane.

The study provides insights into the impact of different getter substrates on the hydrogenation process and highlights the importance of understanding the breakdown of materials used in the process. The findings can aid in the development of more efficient and effective getter materials, which can mitigate unwanted reactions with component materials and maintain vacuum in electrochemical systems, capture iodine, and purify gases for storage.

(1) Davis, J. T.; Beaux II, M. F.; Freye, C. E. Evaluation of different getter substrates using two-dimensional gas chromatography with time of flight mass spectrometry. J. Chromatogr. A 2023, 1689, 463760. DOI: https://doi.org/10.1016/j.chroma.2022.463760