Efficient hydrogen (H₂) evolution through the (photo)electrochemical splitting of water is essential to drive a green hydrogen economy. At solar-to-hydrogen (STH) efficiencies around 10 %, the average price of H₂ produced is slightly higher than $10 000 ton^-1 [1]. The current market value of hydrogen from steam methane reforming is only $1 400 ton^-1 [1-2], implying that there is little incentive for the development of alternative processes for H₂ production. Hence, the economic profitability of hydrogen production through (photo)electrochemical water splitting must be increased. A suitable route might be the simultaneous production of high-value chemicals at the anode.

In ‘classic’ electrochemical water splitting, oxygen is formed at the anode [2]:

2 H₂O → O₂ + 4H⁺ + 4e^-                                                                                      E⁰ (O₂/H₂O) = 1.23 V vs RHE

The net worth of O₂, however, is only $35 ton^-1. An alternative anodic reaction is the selective partial oxidation of water to hydrogen peroxide (H₂O₂) [2]:

2 H₂O → H₂O₂ + 2H⁺ + 2e^-                                                                                E⁰ (H₂O₂/H₂O) = +1.78 V vs RHE

With a net worth value of $500-1200 ton^-1 and a growing H₂O₂ demand, hydrogen production with concomitant H₂O₂ has great promise in future (photo)electrochemical applications. Although not many reports have been published on anodic H₂O₂ production, the feasibility has recently been demonstrated theoretically and experimentally. In particular, BiVO₄ has been referred to as a promising (photo)electrocatalyst [3-4]. Furthermore, it has been advocated that using bicarbonate as an electrolyte is essential to achieve high selectivity for anodic H₂O₂ production.

In this work, we present a techno-economic analysis to address whether H₂O₂ production at the anode as an alternative to oxygen is a feasible method to make (photo)electrochemical H₂ production economically more attractive for industry. The minimum hydrogen prices that can theoretically be achieved to reach a break-even-point will be discussed. Furthermore, we performed a sensitivity analysis to demonstrate which parameters need to be optimized to realize these hydrogen prices as quickly as possible. Using the same means, we will elaborate on the techno-economics of simultaneous anodic and cathodic H₂O₂ production as well. Finally, we confirm experimentally that selective partial oxidation of water to H₂O₂ is possible. Challenges that need to be overcome will be discussed.