8.4 adsorption at gas /solid interface Levine pp 397-402 section 13.5 adsorption of gases on Sollas
§8.4 adsorption at gas / solid interface Levine: pp. 397– 402 section 13.5 adsorption of gases on solids
8.4.1 solid surface and specific surface area
8.4.1 solid surface and specific surface area
8. 4. I solid surface and specific surface area (1) Surface of solid: unbalanced force and suspending bond S Surface layer: enlarged interlayer space Suspending bond Single atom catalyst, is it real? Matter that is at or near an interface is not in the same state as those in the interior of a phase. Owing to the suspending bond solid surface is apt to react with other substances How de we stabilize the solid surface?
Si Suspending bond Surface layer: enlarged interlayer space Matter that is at or near an interface is not in the same state as those in the interior of a phase. Owing to the suspending bond, solid surface is apt to react with other substances. How de we stabilize the solid surface? (1) Surface of solid: unbalanced force and suspending bond 8.4.1 solid surface and specific surface area Single atom catalyst, is it real?
8. 4. I solid surface and specific surface area (1) Surface of solid: unbalanced force and suspending bond Unstable Supported metal E 高 nanoparticle catalysts EA Stable (d) Eo Dispersion activation energy single-atom catalysts EA AgGregation activation energy (EA ED) 检索结果:139 来自所有数据库 您的检索:标题 Fig. 8 Charge differences (isosurface value 0.0015 e A-) for (a)O2a ( catalyst)AD标题 s Vig-C3Na.(b) O2aCulg-C3N4(c) Coevig-CN and(d) oav/g-C3Na ( single atom)… The red and green colors represent charge accumulation and depletion
检索结果: 139 (来自 所有数据库) 您的检索: 标题 : (catalyst) AND 标题 : (single atom) ... (1) Surface of solid: unbalanced force and suspending bond 8.4.1 solid surface and specific surface area
8. 4. I solid surface and specific surface area (2) Degree of subdivision 400mJm×6×103m2=2400J arris Surface area Surface atom % cm 6 cm- 3×108 1um6×104cm2 30% lnm6×107cm ~100% (3)Specific area: The surface-to-volume/mass ratio
arris Surface area Surface atom % 1 cm 6 cm2 3 10-8 1 m 6 104 cm2 30% 1 nm 6 107 cm2 ~ 100 % (2) Degree of subdivision (3) Specific area: V S Sv = W S Sw = The surface-to-volume / mass ratio 400 mJm-2 6 103 m2 = 2400 J 8.4.1 solid surface and specific surface area
8. 4. I solid surface and specific surface area 3)Danger of suspending powder Powder explosion in Baxian, Xinbei, Taiwan Micropowder explosion: micropowder is thermodynamically unstable http://www.igiyi.com/w19rt68ph15.html
Powder explosion in Baxian, Xinbei, Taiwan http://www.iqiyi.com/w_19rt68ph15.html 8.4.1 solid surface and specific surface area Micropowder explosion: micropowder is thermodynamically unstable. (3) Danger of suspending powder
8.4.2 adsorption on solid surface
8.4.2 adsorption on solid surface
8.4.2 adsorption on solid surface (1) The way to stabilize solid surface Sorption: movement of a material from Solid can not lower surface energy by one phase to another Adsorption vs shrinking its surface. How can solid lower absorption its surface energy? ●s Adsorbed Suspending bonds? molecules High surface energy? solid Adsorption of gas molecules
Solid can not lower surface energy by shrinking its surface. How can solid lower its surface energy? gas solid Adsorbed molecules Adsorption of gas molecules (1) The way to stabilize solid surface 8.4.2 adsorption on solid surface Suspending bonds? High surface energy? Sorption: movement of a material from one phase to another. Adsorption vs. absorption
8.4.2 adsorption on solid surface (2)Characteristics of adsorbents a b Material surface area (m2g-1) MnFeoactivated carbon 553 magnetic composites Activated Carbons from 821 Agricultural Residues 500 n Activated carbon prepared from.53 lignin Powdered activated carbon 1100--1230 Activated carbon Fiber 1153.25 Adsorbate: the material being adsorbed Commercial activated carbon 1200 Adsorbent: the material doing the Activated carbons from Iris 137 adsorbing tectorum doped with ferric nitrate NaOH-activated carbon produced1524 from macadamia nut shells
(2) Characteristics of adsorbents 8.4.2 adsorption on solid surface Material Specific surface area (m2 g −1) MnFe2O4 /activated carbon magnetic composites 553 Activated Carbons from Agricultural Residues 821 Activated carbon prepared from lignin 931.53 Powdered activated carbon 1100---1230 Activated Carbon Fiber 1153.25 Commercial activated carbon 1200 Activated carbons from Iris tectorum doped with ferric nitrate 1371 NaOH-activated carbon produced from macadamia nut shells 1524 Adsorbate: the material being adsorbed. Adsorbent: the material doing the adsorbing
8.4.2 adsorption on solid surface (3)Kind of adsorption chemical adsorption physical adsorption chemisorption, physisorption V cm
chemical adsorption, physical adsorption chemisorption, physisorption (3) Kind of adsorption 8.4.2 adsorption on solid surface
