Ten years ago, I had an explosion in an electrolytic experiment. The cathode was a palladium tube 2mm OD, and 1.6 mm ID. The anode was a platinium wire, and the electrolyte was LiOD and D2O. It was an open cell, and I was doing mass flow calorimetry. The experiment had been running for a few weeks with increasing and decreasing input powers. A Monday morning when I opened my lab, there was glass everywhere, the cell had exploded. It was a 50 cm long 2.5 cm ID Dewar, and it had exploded. The system was not sealed. I don't know what happened. I tried later to create a D2+O2 explosion in a similar design, but the result was a firecracker style explosion. No destruction of the Dewar. Since then I stopped elctrochemistry, and if I ever go back, I will place a steel tube around the cell to protect myself.
I have been doing mass flow calorimetry in gas phase for 15 years, and my calorimeter is all stainless steel. I always work with very small amounts of materials, and increase the temperature by steps, so that I can monitor the experiment carefully. I will never go full power at once. At the moment, I am trying to duplicate Parkhomov experiment, but for safety and convenience, I use a steel tube 6mm OD and 4mm ID with .5g of Ni and .05g of LiAlH4. I increase the temperature by small steps, and it takes several days for me to reach 1000°C. That way, I can see if there is any sign of exccess heat appearing at any time. This also gives me confidence in the actual heat I measure, because, even with a mass flow calorimeter, it is necessary to make a calibration. There are always heat losses that are neither constant, nor proportional.
Regarding the chemicals, it is a question of quantities, the smallest the safest. I am not trying at this point to get a COP of 3, but 1.2 or 1.3 is sufficient for me to conclude. So this is what I am aming at.
I hope to make a contribution at the ICCF19 conference.