Electrochemical cell and method of processing a gaseous stream containing hydrogen

An electrochemical cell 1 comprising an anodic half-cell 5 having an inlet 2 receiving hydrogen at a first pressure, a cathodic half-cell 6 having an outlet 3 transferring hydrogen at a second pressure, and a power source. A membrane electrode assembly (MEA) 4 separates the half-cells and comprises anodic and cathodic electrodes separated by an anion exchange membrane (AEM). Hydroxyl anions cross the membrane instead of hydrated protons and the cathode reaction consumes water to produce H2, intended to result in dry hydrogen gas. The MEA may comprise one or more catalysts, preferably not a platinum group metal. The AEM comprises hygroscopic particles arranged in a concentration gradient with a higher concentration on the cathodic side. The power source is preferably reverse pulse, allowing purge of poisons from the electrodes. Also disclosed are a hydrogen sensor and apparatus for stripping hydrogen from a gaseous stream, each comprising the cell.