[thetada]

I've been thinking about electrolysis of water to make hydrogen. What is the value of seeking superior catalysts? No matter the catalyst, you'll only get out what you put in, energy wise, or rather less. Catalysis will increase the rate at which water is broken down into its elements, meaning less electrical energy will be used than without the catalyst. However, this amount of electricity will always exceed the amount that will be produced when the gases are recombined in a fuel cell. So the point of catalysis is that the enterprise becomes slightly less unprofitable but not profitable?

[Arkcon]

I'm nor following the entire premise.  What catalyst for this reaction do we have?  How will such a catalyst increase the reaction?  There is only one reactant, water.  How will the catalyst help the water find ...what?

[thetada]

I suppose I can simplify the question like this: what value does a catalyst for water-splitting have when the energy output by the fuel cell is still going to be just less than the energy input to the water electrolysis process? Here's a link referencing research into catalysis for water electrolysis:

https://www6.slac.stanford.edu/news/2016-03-24-new-catalyst-three-times-better-splitting-water.aspx

[Babcock_Hall]

Consider photosynthesis.  Strictly speaking, it does not produce hydrogen gas, but it produces reducing equivalents in the form of NADPH.