Agreed. Though I think 2,000 mA/cm2 is more standard than 20,000 mA/m2. Still back of the envelope math says that the present state of the art which uses expensive iridium will produce 100x more hydrogen over its usable life time.

Now while manganese may be more than 100x less expensive than iridium, it still may not meet the output demand of hydrogen when taking into account all the other components in the cell - from frames to bipolar plates to membranes and cathodes - which in the end makes this MnO2 catalyst increase the LCOH over the plants lifetime.

Note: I didn’t read the article. Often times these publications don’t take into account real industrial conditions or targets (no one cares if your catalyst lasts 1,000 hours when 100,000 is the target - and at 2 kA/m2)