应《网络安全法》要求，自2017年10月1日起，未进行实名认证将不得使用互联网跟帖服务。为保障您的帐号能够正常使用，请尽快对帐号进行手机号验证，感谢您的理解与支持！

24小时热门版块排行榜    

小木虫论坛-学术科研互动平台 » 化学化工区 » 催化 » 催化剂制备 » 请问分子筛制备中水和Na2O的问题
51/1返回列表
查看: 490  |  回复: 5
只看楼主 @他人 存档 新回复提醒 (忽略) 收藏    在APP中查看
当前主题已经存档。
当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

duyuhai

铁杆木虫 (正式写手)

[交流] 请问分子筛制备中水和Na2O的问题

最近在试制Y型分子筛。
手册上讲到，feed gel的时候，给出了这样一个式子：10.67Na2O:Al2O3:10SiO2:180H2O
请问，这里的180H2O是经过计算得到的，还是后来测定的？制备这样的凝胶，所需的水的量真的只能按摩尔比算出是这样的么？

另外，我按他投料比计算了一下Na2O的量不足这个比例。差不少。请问，NaOH的投料量是一定要按比例来还是可以多一些？？

先谢谢了！

PS：如果哪位有Y型分子筛的详细制备步骤并且愿意共享，有更多金币相赠~
回复此楼

» 猜你喜欢

» 本主题相关商家推荐: (我也要在这里推广)
1楼 2008-07-15 16:56:18
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dj_king

铁杆木虫 (著名写手)
★ ★ ★ ★ ★
duyuhai(金币+5,VIP+0):多谢了~
上述计算中应把NaOH中的H2O算进去。如果Na/Al=1.27 符合(Na2O)1.27(AL2O3)，其它计算我看没问题了。
Notes a和g都说明该配方可以微调，估计按照给出的原料折算的投料比，或是最后的胶体组成折算的投料比都可以成功做出来。
赞一下(1人) 回复此楼
快乐不打折
5楼2008-07-16 22:14:18
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 6 个回答

dj_king

铁杆木虫 (著名写手)
★ ★
^_^@^_^(金币+2,VIP+0):QQQ
FAU
Linde Type Y
Si(71), Al(29)


Contributed by David Ginter

Verified by G. Price andby C. Kuntz

Type Material Na56[Al56Si136O384] : 250 H2O

Method D. M. Ginter, A. T. Bell and C. J. Radke [1]

Batch Compositiona

Seed Gel (5% of Al): 10.67 Na2O : Al2O3 :10 SiO2 : 180 H2O
Feed Stock Gel (95% of Al): 4.30 Na2O : Al2O3 : 10 SiO2:180 H2O
Overall Gel: 4.62 Na2O : Al2O3 : 10 SiO2 : 180 H2O

Source Materials

deionized water
sodium aluminate solid (Strem Chemicalb 1.27 Na/Al, 6.1% H2O)
sodium hydroxide pellets (J. T.Baker, 99% NaOH)
sodium silicate solution (PQ Corp, N Brand, 28.7 wt% SiO2, 8.9 wt% Na2O)c

Batch Preparation (for 32 g anhydrous product)

Seed Gel

(1) [19.95 g water + 4.07 g sodium hydroxide + 2.09 g sodium aluminate], stir in 50 mL plastic bottle until dissolved
(2) ((1) + 22.72 g sodium silicate solution], stir moderately for at least 10 minutes; after stirring, cap the bottle and let the solution age at room temperature for 1 dayd

Feedstock Gele

(3) [130.97 g water + 0.14 g sodium hydroxide + 13.09 g sodium aluminate], stir in a 500 mL plastic beaker until dissolved
(4) [(3) 142.43 g sodium silicate solution], stir vigorously with a high-shear turbine mixerf until the gel appears somewhat smooth; cover the beaker until the addition of the seed gel

Overall Gel

(5) [(4) + 16.50 g of (2)], slowly add seed gel (2) to feedstock gel (4) under high shear;f move the beaker during mixing to ensure the entire gel volume encounters the high shear from the turbine (up to 20 minutes)g

Crystallization

Vessel: 300 mL polypropylene bottle (sealed)
Incubation: One day at room temperature g Temperature: 1000C g
Time: After about 5 h, the gel will separate into a solid (containing the NaY Zeolite) that will settle to the bottom, and a hazy supernatant liquid. Continue heating until the supernatant is clear indicating complete crystallization (no more than 2 additional hours)g

Product Recovery

(1) Centrifuge; decant supernatant
(2) Filter the wet solid product; wash with distilled water until pH of filtrate is below 9
(3) Dry at ll0¡C
(4) Yield: approximately 32 g of anhydrous NaY (about 98% on Al2O3)

Product Characterization

XRD FAU; characteristic strong reflections at d = 14.28, 8.75 and 7.46 Å, a0 = 24.72 Å.
Competing phases (if present): GIS, GME, CHA
Elemental Analysis; NaAlO2. 2.43 SiO2
Crystal Size and Habit: octahedral crystals, <1 um
Click here to view XRD pattern

References

[1] D. M. Ginter, A. T. Bell, C. J. Radke, in Synthesis of Microporous Materials, Vol. 1, Molecular Sieves, M. L Occelli, H. E Robson (eds.), Van Nostrand Reinhold, New York, 1992, p 6
[2] T. Linder, C. Kurtz, personal communications

Notes

a. This procedure is reliable only for the production of submicron NaY crystals and is limited in the range of sizes and compositions that can be produced using slight procedural modifications.

b. Also available as solutions with this Na/Al ratio from Alcoa and U. S. Aluminate.

c. It should be clear of precipitated material.

d. Solution is clear when prepared; during aging, a loose gel forms which contains the NaY seeds.

e. May be prepared concurrently with the seed gel or just prior to mixing the overall gel.

f. 1600 rpm with 2.5 inch diameter, 4 paddle radial mixer (minimum) recommended.

g. If a GIS (NaP) impurity is produced, it can be eliminated by reducing the Na aluminate in (1) to 1.40 g and aging the seed gel for 1 to 5 days prior to blending it into the feedstock. Further aging of the composite is optional with this seed, and pure product has been obtained after crystallization at 900C for 22 hours [2]
赞一下(11人) 回复此楼
快乐不打折
2楼2008-07-15 21:42:17
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dj_king

铁杆木虫 (著名写手)
★ ★ ★ ★
buffaloli(金币+4,VIP+0):多谢，辛苦了！
你的配比就是上面这个，是seed不是feed。
这是经过验证的配方，不会有问题的。180H2O是经过计算得到的，seed gel的配比可以稍有变化。计算上述配比时，仔细看清楚原料，把原料中的Na都折算成Na2O。
赞一下(10人) 回复此楼
快乐不打折
3楼2008-07-15 21:51:13
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

duyuhai

铁杆木虫 (正式写手)
buffaloli(金币+0,VIP+0):那上面的方太豪华了，呵呵
不好意思，上面的确是我打错了。这个方法出自《Verified Synthesis of Zeolitic Materials》第二版。因为我的原料和他的不大一样，所以应该是要换算一下的。我按照它给出的方法计算出来的seed gel比例是：8.96Na2O : Al2O3 :10 SiO2 : 166 H2O（计算过程在后面，帮我看看有否漏掉什么，或者有计算错误。谢谢！），那么，究竟是按照他给出的原料折算，还是按照最后的胶体组成折算投料比呢？
再一次感谢您！
ＰＳ，您把晶化温度贴错了，是１００℃，不是１０００Ｃ
----------------------------------------------------------------------------
19.95 g H2O ~~~ H2O  1.10833 mol

4.07   g NaOH ~~ Na2O 0.050875 mol

2.09   g 偏铝酸钠中，
  水有6.1%（应该是wt%）为 0.12749g  合 0.007083 mol
  Na/Al=1.27 ，应该符合(Na2O)1.27(AL2O3)（分子量：62*1.27+102=180.74），这部分质量为 2.09*0.939=1.96251 g
  则，Na2O 1.96251/180.74*1.27= 0.013790 mol
        Al2O3 1.96251/180.74= 0.010858 mol
22.72 g  硅酸钠溶液中：
  SiO2：22.72*0.287=6.52064 g ~~ 0.108677 mol
  Na2O：22.72*0.089=2.02208g ~~ 0.032614 mol
  H2O ：22.72*0.624=14.17728g ~~ 0.787627 mol
这样
Na2O：0.050875(NaOH)+0.013790(偏铝酸钠)+0.032614(硅酸钠)=0.097279 mol
Al2O3 ：0.010858 mol （只有偏铝酸钠的）
SiO2 ：0.108677 mol （只有硅酸钠的）
H2O ：1.10833(加的水)+0.007083(偏铝酸钠)+0.787627(硅酸钠溶液)=1.805573 mol

最后是8.96Na2O : Al2O3 :10 SiO2 : 166 H2O

[ Last edited by duyuhai on 2008-7-16 at 19:33 ]
赞一下(10人) 回复此楼
4楼2008-07-16 17:00:37
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 6 个回答
普通表情 龙 兔 虎 猫 高级回复 (可上传附件)
信息提示
关闭
请填处理意见
关闭