Selectivity and resistance to poisons of commercial hydrogen sensors

Abstract

PoisonsInhibitors Interferents a b s t r a c tThe resistance of several models of catalytic, workfunction-based metal-oxide-semiconductor and electrochemical hydrogen sensors to chemical contaminants such as SO 2, H 2 S, NO 2 and hexamethyldisiloxane (HMDS) has been investigated. These sensor platforms are among the most commonly used for the detection of hydrogen. The evaluation protocols were based on the methods recommended in the ISO 26142:2010 standard. Permanent alteration of the sensor response to the target analyte (H 2 ) following exposure to potential poisons at the concentrations specified in ISO 26142 was rarely observed.Although a shift in the baseline response was often observed during exposure to the potential poisons, only in a few cases did this shift persist after removal of the contaminants.Overall, the resistance of the sensors to poisoning was good. However, a change in sensitivity to hydrogen was observed in the electrochemical platform after exposure to NO 2 and for a catalytic sensor during exposure to SO 2 . The siloxane resistance test prescribed in ISO 26142, based on exposure to 10 ppm HMDS, may possibly not properly reflect sensor robustness to siloxanes. Further evaluation of the resistance of sensors to other Si-based contaminants and other exposure profiles (e.g., concentration, exposure times) is needed.

Ultrasensitive H2S gas sensors based on p-type WS2 hybrid materials

“…Grain size reduction to the nanometer range and relatively easy sensitization to various analytes (via either lattice doping with anions and cations or surface decoration with metals and metal oxides) have emerged as key strategies to improve their detection properties [2,3]. The main drawbacks of current metal oxide-based devices are associated with their typically high operating temperatures (several hundreds of degrees) and limited use in environments containing even traces of sulfur and sulfides, because of the easy poisoning of the catalytically active surfaces involved in the adsorption and sensing of analytes [4]. In principle, other types of gas sensors whose operation is based on, e.g., gas ionization [5] or changes in the optical properties of waveguides [6], may represent alternative solutions; however, their typical detection limits are at most a few parts per million of analyte.…”

Влияние водорода на термоэлектрический сигнал напряжения в слоистой структуре Pt/WO-=SUB=-x-=/SUB=-/6H-SiC/Ni/Pt

“…Это явление используется для детектирования H 2 в O 2 -содержащих газовых смесях специальными термоэлектрическими сенсорами [4]. Такие сенсоры обладают хорошими техническими характеристиками, но термоэлемен-ты и катализаторы имеют специальную архитектуру и относительно большие (миллиметровые) размеры, что создает проблемы их встра-ивания в многофункциональные датчики, изготавливаемые на одном чипе [5].…”

Multifunctional polyaniline/chloroplatinic acid composite material: Characterization and potential applications

“…Recent literature focused on different technological applications of the new composite materials obtained by combining the conducting polymers with metal catalysts . As the platinum group metals have a catalytic effect , they can be used in various technological applications such as fuel cells , sensors , photocatalytic , and electro‐optical devices . Hence, the interest in polymer matrix composites containing platinum based inorganic compounds increased due to a high number of important cutting‐edge applications stated above.…”