Industrial-level alkynols electrocatalytic semi-hydrogenation using seawater as hydrogen source offers a sustainable alternative to conventional thermocatalytic routes, yet remains limited by the lack of efficient and robust electrocatalysts. Here, we report the synthesis of Nd1Gd1 dual atomic site on metallene for co-production of alkenol and magnesium hydroxide in the seawater system. Nd1Gd1Pd metallene achieves a selectivity of ≈96. 7% and a Faradaic efficiency of ≈87. 3% for the conversion of 2-methyl-3-butyn-2-ol to 2-methyl-3-buten-2-ol at −150 mA cm-2 in a flow-cell system, and maintains ≈98. 0% selectivity at 1. 2 A for over 300 h of continuous operation, achieving the long-term stable co-electrosynthesis of alkenols and magnesium hydroxide in natural seawater at industrial-scale currents. Techno-economic analysis reveals a projected product revenue of at least 8, 499 per ton of 2-methyl-3-buten-2-ol, underlining the industrial viability of this process. Mechanism investigations illustrate dual hydrogen-spillover and co-catalytic effects on Nd1Gd1Pd, promoting migration-reaction coupling mechanism of reactive *H to synergize hydrogenation. This work provides a seawater electrocatalytic semi-hydrogenation system and proposes an optimization strategy by atomically engineered dual hydrogen-spillover effect. Seawater-based electrocatalytic semi-hydrogenation offers a sustainable route to produce alkenols but is hindered by inefficient catalysts. Here, the authors report a dual-site Nd–Gd metallene catalyst that enables co‑production of alkenols and magnesium hydroxide directly from natural seawater.
Mao et al. (Wed,) studied this question.