Water electrolysis enhanced by super gravity field for hydrogen production

Water electrolysis was carried out galvanostatically under a super gravity field. The relationships of cell voltage, ohmic voltage drop reduction and overpotential reduction with gravity coefficient (G) and current densities were studied. It was found that water electrolysis was noticeably enhanced by the super gravity field. Good linear relationships between cell voltage (U) and logarithm of G can be obtained at all current densities. Large cell voltage reduction was achieved under the super gravity field, especially under higher gravity and at higher current densities. Energy savings were about 9-17% at 0.5 A cm(-2) under the super gravity field. The cell voltage reduction was ascribed to ohmic voltage drop reduction and overpotential reduction. The share of ohmic voltage drop reduction (i Delta R-G) in cell voltage reduction (Delta U-G) was higher than 70% at all current densities. At constant cell voltage, the rate of hydrogen produced under super gravity field increased noticeably compared to that under normal gravity condition. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.