Overview
Ortho hydrogen (o-H₂) is one of the two spin isomers of molecular hydrogen, distinguished by the parallel alignment of its two proton spins. It exists in equilibrium with para hydrogen (p-H₂), its antiparallel spin counterpart, with the ratio dependent on temperature. At room temperature, the ortho:para ratio is approximately 3:1 due to statistical nuclear spin distribution. Unlike para hydrogen, ortho hydrogen cannot relax to the lower-energy para state without an external catalyst, making it metastable under normal conditions. This property is critical in cryogenic applications, where uncontrolled ortho-para conversion can lead to significant heat release.
Physical and Chemical Properties
Ortho hydrogen shares most physical properties with normal hydrogen (a mixture of ortho and para forms), including boiling point and density. However, its nuclear spin configuration gives it distinct spectroscopic signatures, particularly in rotational spectroscopy where ortho-hydrogen shows odd rotational quantum numbers (J=1,3,...) due to symmetry constraints. Thermodynamically, ortho hydrogen has approximately 1.06 kJ/mol higher energy than para hydrogen at low temperatures. This energy difference becomes negligible above 200K. The ortho-para conversion is exothermic, releasing up to 527 J/g when catalyzed, a consideration in liquid hydrogen storage systems.
Main Applications
In cryogenics, ortho hydrogen's conversion heat affects liquid hydrogen storage efficiency. Industrial hydrogen liquefaction plants often include catalytic converters to produce para-enriched hydrogen (typically >95% p-H₂) to minimize boil-off losses. Ortho hydrogen is also studied in fundamental physics experiments testing quantum mechanics and nuclear spin interactions. NASA and other space agencies have researched ortho-para separation for advanced rocket propulsion, as the spin isomers exhibit different combustion characteristics. In NMR spectroscopy, ortho hydrogen serves as a model system for studying dipolar coupling and spin relaxation mechanisms in simple diatomic molecules.
Safety and Storage
As a flammable gas, ortho hydrogen requires standard hydrogen safety protocols - leak prevention, inert atmosphere handling, and explosion-proof equipment. The additional hazard of ortho-para conversion heat necessitates careful thermal management in cryogenic systems. Large-scale storage typically uses double-walled vacuum-insulated containers with catalytic converters. For laboratory use, ortho-enriched hydrogen is usually prepared on-demand via thermal equilibration at high temperatures (where ortho dominates) followed by rapid quenching. Long-term storage as pure ortho hydrogen is impractical due to gradual spontaneous conversion to the para form, even at low temperatures.
B2B Procurement Guide
Ortho hydrogen is not typically sold as a standalone commercial product. Most B2B transactions involve specialized gas suppliers who can provide custom spin-isomer mixtures for research purposes. Key procurement considerations include required ortho:para ratio (typically specified as % ortho), delivery pressure, and container type (gas cylinders or cryogenic dewars). For industrial hydrogen users needing para-enriched product, catalytic conversion units are available as separate equipment. Pricing depends on scale and purity, with small-scale research quantities (liter quantities) costing significantly more per unit than bulk industrial hydrogen. Lead times may be longer than standard hydrogen due to specialized production requirements.
Related Manufacturers
- 主营：皮带轮、三角带轮、风机轴盘、hrc联轴器、多楔带轮、铸铁联轴器、传力皮带盘、梅花联轴器、电机专用轮、双槽铸铁三角、直径三角皮带
- 主营：异辛醇、乳化剂、乙烯醚、正十六烷、醚羧酸、脂肪醇、分散剂、染色助剂、聚乙二醇、异构醇醚、泊洛沙姆、椰油酰胺、基羟乙基、烷基糖苷、特辛基酚、聚氧乙烯、嵌段聚醚、单油酸酯、异构十三醇、丙烯磺酸钠、氢化蓖麻油、丙烯酰胺基、醇醚葡糖苷、低泡渗透剂、甲酯乙氧基、癸基葡糖苷
- 主营：多聚甲醛、环己胺、异丙醇、正硅酸乙酯28 40、正十二烷、无水乙醇、铬酸酐、亚氯酸钠、二甲基甲酰胺、硫酸羟胺、戊二酸二甲酯、邻苯二甲酸二乙酯、二甲苯、二氯甲烷、环己烷、四氯乙烯、环己酮、环氧氯丙烷、甲醇、甲酸、乙腈、苯酚、乙二醇乙醚醋酸酯、醋酸丁酯
- 主营：二甲基亚砜、乙二醇、丙二醇、DMAC
- 主营：色谱试剂、环保试剂、卡尔费休试剂、正丙胺、无水试剂
- 主营：十六烷基三甲基溴化铵、十二烷基甜菜咸、乳化剂、正十烷、亚磷酸三丁酯、棕榈油、钛酸四丁酯、钛酸四乙酯
- 主营：胰蛋白胨、骨蛋白胨、牛肉浸膏、乙酰正丙醇武汉现货、福美钠、漂粉精、漂白精、次氯酸钙、单乙醇胺、三乙醇胺、三甘醇、防辐射钡粉、茶皂素、大苏打、小苏打、甘氨酸、九水硫化钠
- 主营：脱模剂、碘酸钾、磷酸镁、正钒酸钠质量保障、维生素c、维生素b1、维生素b6、维生素d3、二硫化钼、吡啶硫铜、香草香精、芥酸酰胺、乙基纤维素、次氯酸钙、九水硫化钠、EVA乳液、水玻璃、硅酸钠
- 主营：无水乙醇、实验室溶剂、无水甲醇、正丁醇、四氢呋喃、乙腈、二氯甲烷、二甲基甲酰胺、异丙醇、苯甲醇、丙三醇、甘露醇、十六醇、十八醇、草酸、磷酸、硼酸、碘化钾、标准溶液、实验室耗材
- 主营：十八硫醇、碳酸铯、猪胆酸钠、脱氧胆酸钠、石胆酸、钛酸酯偶联剂、乙烯硫脲、单磷酸钠、玫瑰草油、乙酰化透明质酸钠、吗啉丙磺酸、亚甲基双丙烯酰胺、氧化锌、二甲基吡啶、聚醋酸乙烯酯、对碘苯甲酸甲酯
- 主营：硼酸酐、阻聚剂、己二酸、正癸醇、氯化锂、发泡剂、乙二醇、醋酸铜、硅酸钠、新癸酸、环烷油、腰果酚、十二醇、酒石酸、碳酸锂、三甘醇、油菜酸、二甘醇、碳酸钾、甲酸钠、硅酸镁、棕榈油、6-氯嘌呤、微晶石蜡、磷酸一铵
- 主营：增塑剂、草酸镍、阻燃剂、正辛烷、栀子蓝、抗氧剂、偶联剂、异壬酸、1-二十烯、间氟溴苄、异胞嘧啶、磷酸三钾、油墨油剂、洗涤助剂、苯磺酸钠、单体香料、环磺酮酸、分散染料、无机颜料、苹果酸镁、表面处理剂、丙二醇甲醚、化妆品原料、丁酸甘油酯、硅烷处理剂、表面活性剂
- 主营：乙酸镁、阻燃剂、热熔胶、正十六烷、聚合物、锂电池、光电极、泡泡糖、氯丁胶、碳酸镉、新癸酸、补差价、稀释剂、羟乙基、氧化铝、氧化铜、甲酸钾、c/c材料、碳酸锰、玻璃粉、硬光油、防腐剂、氧化铋、防水剂、聚丙烯、增粘树
- 主营：辐射探测器用双面镀铝、耐高温CPI膜、耐候氟膜、45度正投影膜、45度幻影成像投影膜、打孔膜及打孔加工、镀金属膜、功能性PET膜
- 主营：台球桌、巧克粉、遮阳伞、双拍正、台球杆皮、乒乓球台、真皮篮球、双顶罗马伞、二合一桌球台、斯诺克台球杆、斯洛克台球杆、美式黑八台球、室外比赛篮球、室内乒乓球桌、健身初学球拍、眼镜分体球杆、台球实木三角架、全碳素羽毛球拍、经典雕刻桌球桌