Electrolysis system including at least one capacitive half-cell

An electrochemical system comprising

• a first half-cell (1, 100) adapted for holding a first electrolyte, a first electrocatalyst (10) arranged on a current collector (11) forming a first working electrode, and a first auxiliary electrode material (12) arranged on a second current collector (13) forming a first auxiliary electrode;
• and
• a second half-cell (2, 200) adapted for holding a second electrolyte, a second electrocatalyst (20) arranged on a current collector (21) forming a second working electrode, and a second auxiliary electrode material (22) arranged on a current collector (23) forming a second auxiliary electrode;
• wherein the working electrodes are connected to an external circuit including a power supply (300), and a control unit (400), and the auxiliary electrodes are connected to each other, forming a closed circuit, said system further comprising at least a first (130) and second electrolyte reservoir (230), a first (140) and a second (240) pump for circulating a first electrolyte between said first half-cell (1, 100) and said first reservoir (130), and circulating a second electrolyte between said second half-cell (2, 200) and said second reservoir (230), and a first (150) and a second (250) container for collecting gas formed in each electrolytic half-cell respectively.