Rationally Designed PdAuCu Ternary Alloy Nanoparticles for Intrinsically Deactivation-Resistant Ultrafast Plasmonic Hydrogen Sensing

Abstract

Hydrogen sensors are a prerequisite for the implementation of a hydrogen economy due to the high flammability of hydrogen-air mixtures. They are to comply with the increasingly stringent requirements set by stakeholders, such as the automotive industry and manufacturers of hydrogen safety systems, where sensor deactivation is a severe but widely unaddressed problem. In response, we report intrinsically deactivation-resistant nanoplasmonic hydrogen sensors enabled by a rationally-designed ternary PdAuCu alloy nanomaterial, which combines the identified best intrinsic attributes of the constituent binary Pd alloys. This way we achieve extraordinary hydrogen sensing metrics in synthetic air and poisoning gas background, simulating real application conditions. Specifically, we find a detection limit in the low ppm range, hysteresis-free response over 5 orders of magnitude hydrogen concentration, sub-second response time at room temperature, long-term stability and, as the key, excellent resistance to deactivating species like carbon monoxide, notably without application of any protective coatings. This constitutes an important step forward for optical hydrogen sensor technology, as it enables application under demanding conditions and provides a blueprint for further material and performance optimization by combining and concerting intrinsic material assets in multicomponent nanoparticles. In a wider context, our findings highlight the potential of rational materials design through alloying of multiple elements for gas sensor development, as well as the potential of engineered metal alloy nanoparticles in nanoplasmonics and catalysis.

A Library of Late Transition Metal Alloy Dielectric Functions for Nanophotonic Applications

“…It was not until very recently, enabled by the development of the corresponding nanofabrication methods, that systematic investigations of the fundamental properties of noble metal alloy nanostructures started to appear. [ 2–10 ] Some of these materials have already found applications, for example in plasmonic hydrogen sensors, [ 11,12 ] or are suggested for the use in plasmon‐mediated catalysis. [ 13 ]…”

New Aspects of Platinum Group Metal‐Based Solid‐Solution Alloy Nanoparticles: Binary to High‐Entropy Alloys

“…To date, various ternary and quaternary alloy NPs have been reported to show enhanced catalytic performance or physical properties, such as Co‐Pd‐Au, Co‐Pd‐Pt, Fe‐Ru‐Pt, Ru‐Pd‐Ir, Ni‐Pd‐Pt, Cu‐Pd‐Au, Pd‐Ag‐Ni, Pd‐Cu‐Bi‐Mn, Pd‐Rh‐Pt‐Ag, Co‐Ni‐Cu‐Pt, and others.…”

Metal Hydride Based Optical Hydrogen Sensors

“…The catalytic Pd surfaces are prone to poisoning by humidity and chemical species such as NO x and CO, all omnipresent in atmospheric conditions. [25][26][27][28] To improve the reproducibility of the signal in realistic sensing environments, protection layers are needed to keep the Pd surface active. Polytetrafluoroethylene (PTFE) effectively reduces the poisonous effect of humid air.…”

“…Cu to prevent CO poisoning. 28) In the past, Pd-based sensors had a limited cycle lifetime. Due to hydrogenation, thin films may expand up to 30 % in volume resulting in delamination of the film upon repeated cycling.…”

“…Alloying of Pd has often been employed to lower T C and suppress the first order transition. Most frequently, Pd alloys with Au, [33][34][35]48) Ag, 49) Cu 28) and Ta 50) were considered. The sensing characteristics of these materials are largely similar: As exemplified in Fig.…”