Hydrogen “getters” compounded with a solid phase dispersed catalyst are used for scavenging of excess hydrogen in sealed systems to prevent corrosion of nuclear materials, electronic components, and explosion hazards. 1,4-bis (phenylethynyl) benzene (DEB) getters are commonly used as hydrogen scavengers due to their excellent hydrogen uptake capability. These compounds chemically bind H<sub>2</sub>gas through hydrogenation reactions as opposed to physical surface adsorption. Typically, the DEB getters are mixed with activated carbon and Pd nanoparticles, where activated carbon provides surface area to spread getters and Pd acts as a catalyst for hydrogen dissociation (see Figure 1). If in the process of hydrogenation, partially hydrogenated DEB molecules become volatile, then migration of partially hydrogenated DEB away from Pd sites would result in loss of capacity for the DEB/activated carbon/Pd system.<br/>In this work, the equilibrium vapor pressures, melting points, and structures of DEB from virgin state through fully hydrogenated state are probed by the Knudsen cell effusion technique, also known as effusion thermogravimetry and differential scanning calorimetry (DSC) experiments. Furthermore, hydrogenation kinetics are estimated from experiments conducted in isothermal and isobaric reactor conditions. Such kinetic parameters are used for the prediction of DEB getter performance under dynamic hydrogen pressure conditions.

Kinetics of 1,4-bis (phenylethynyl) benzene (DEB) in Pd/C catalyzed hydrogenation

2019 Fall National Meeting

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