An integrated apparatus for production and measurement of molecular hydrogen

Abstract

An integrated apparatus designed to carry out online accurate gas-volumetric (GV) measurements of chemicals generated in a reaction chamber is described here. In particular, such equipment is useful to quantify the molecular hydrogen produced into a small reactor via metal-catalysed hydrolysis of sodium borohydride. In its standard configuration the reactor is coupled to a hydrogenmeter relying on accurate weight measurements of water volumes displaced by the same hydrogen volumes produced during the reaction course. Both static (total gas evolved) and dynamic (rate of evolution) information on the analysed gas-mixture is accessible by such an apparatus. Finally, it can be easily interfaced with other quantitative techniques, such as gas-chromatographic (GC) or flow-measurement (FM) techniques. The apparatus is original in many technical solutions which have been adopted: (i) any kind of catalyst can be tested thanks to the insertion device (interchangeable sample plate, ISP), (ii) catalyst is dipped into solution in situ without system opening, (iii) work conditions are continuously monitored, and (iv) system control and data collection are completely automated. The apparatus has been designed to withstand rough usage, for easy and trouble-free manipulation, rapid and complete gas measurements and easy readability.

Pd-C powder and thin film catalysts for hydrogen production by hydrolysis of sodium borohydride

“…For comparison, the time dependences of stoichiometric hydrogen production yield (%) instead of amount of detected hydrogen (ml) were plotted. Details on the reaction chamber were reported in Zanchetta et al [20]. Fig.…”

Strong activation effect on a Ru-Co-C thin film catalyst for the hydrolysis of sodium borohydride

“…The set of pieces, with the supported catalyst (1–6 mg), was placed at the bottom of a three necked heart-shaped flask. The flask was immersed in a water bath maintained at (25.0 ± 0.5) °C and connected to a gas burette 36 . The SB hydrolysis reaction started by injecting 38 mg of SB (Sigma Adrich 99%) dissolved in 1 ml of 4.5 wt% NaOH solution.…”

“…The SB hydrolysis reaction started by injecting 38 mg of SB (Sigma Adrich 99%) dissolved in 1 ml of 4.5 wt% NaOH solution. The amount of generated hydrogen was determined by measuring the mass of water displaced in the gas burette as a function of time 36 . No additional stirring was used for the experiments, except for the stirring effect of the evolved hydrogen.…”

Ruthenium nanoparticles supported over carbon thin film catalyst synthesized by pulsed laser deposition for hydrogen production from ammonia borane

“…Detailed description of the measurement apparatus can be found elsewhere [42]. For all the reported experiments, fixed volume of above AB solution was maintained at desired temperature and then the catalyst film was inserted into this solution under constant stirring.…”

“…This was possible due to our specially developed catalyst inserting device (descriptions are in ref. [42]). Figure 7 clearly shows that every time the catalyst film is pulled out of the solution, hydrogen production stops, while when inserted back in the solution, hydrogen production restarts.…”