Influence of pH on Molecular Hydrogen (H-2) Generation and Reaction Rates during Serpentinization of Peridotite and Olivine

Huang, Ruifang1; Sun, Weidong2,3,4; Song, Maoshuang5; Ding, Xing5

2019-11

10.3390/min9110661

MINERALS   影响因子和分区

2075-163X

Serpentinization produces molecular hydrogen (H-2) that is capable of supporting communities of microorganisms in hydrothermal fields, which suggests that serpentinization may be closely related to the origin of life at the early history of the Earth and possibly other planets. In this study, serpentinization experiments were performed at 300 degrees C and 3.0 kbar with natural olivine and peridotite as starting reactants to quantify the influence of acidic and alkaline solutions on the processes of serpentinization. The results reveal that acidic and alkaline solutions greatly influence molecular hydrogen (H-2) generation and the rates of serpentinization. Acidic (pH = 2.50) and alkaline solutions (pH = 13.5) increased H-2 production and the rates of peridotite serpentinization. Highly acidic solutions (2 M HCl), however, decreased the production of H-2 after peridotite serpentinization by around two orders of magnitude. The decrease in H-2 production was associated with a sharp decline in the rates of reaction; e.g., when peridotite was reacted with neutral solutions (0.5 M NaCl), 88% of reaction progress was achieved after an experimental duration of 27 days, and the reaction extent decreased by similar to 50% for experiments with highly acidic solutions (2 M HCl) over the same period. In contrast, for experiments with solely olivine, highly acidic solutions (2 M HCl) promoted the rates of olivine serpentinization and H-2 production. The contrasting effect of highly acidic solutions (2 M HCl) on the processes of olivine and peridotite serpentinization may reflect the influence of pyroxene minerals, which could release SiO2 during peridotite serpentinization and, consequently, hydrogen generation and reaction rates may decrease. The experimental results of this study suggest that H-2 production and the rates of serpentinization can be greatly influenced by acidic and alkaline solutions and co-existing minerals (e.g., pyroxene).

olivine serpentinization pyroxene minerals aluminum molecular hydrogen

SCI

英语

第一 ; 通讯

Shenzhen Clean Energy Research Institute[CERI-KY-2019-003]

Mineralogy ; Mining & Mineral Processing

Mineralogy ; Mining & Mineral Processing

WOS:000502267100014

MDPI

Web of Science

1.Southern Univ Sci & Technol, SUSTech Acad Adv Interdisciplinary Studies, Shenzhen 518055, Guangdong, Peoples R China
2.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Shandong, Peoples R China
3.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Shandong, Peoples R China
4.Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
5.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China

Huang, Ruifang,Sun, Weidong,Song, Maoshuang,et al. Influence of pH on Molecular Hydrogen (H-2) Generation and Reaction Rates during Serpentinization of Peridotite and Olivine[J]. MINERALS,2019,9(11).

Huang, Ruifang,Sun, Weidong,Song, Maoshuang,&Ding, Xing.(2019).Influence of pH on Molecular Hydrogen (H-2) Generation and Reaction Rates during Serpentinization of Peridotite and Olivine.MINERALS,9(11).

Huang, Ruifang,et al."Influence of pH on Molecular Hydrogen (H-2) Generation and Reaction Rates during Serpentinization of Peridotite and Olivine".MINERALS 9.11(2019).