Development of a 1 T/1 kA-class AC superconducting coil

Remarkable Promotion Effect of Sulfation over the SiO2‐Supported Vanadium‐Oxide‐Based Catalysts for UHMWPE

“…The characterization results of NH 3 –TPD indicate that the acidity of the catalysts is improved largely after sulfation, while the results of pyridine‐adsorption‐FTIR imply that a large amount of Lewis acid sites and a small amount of Brønsted acid sites are available on the surface of the catalysts. The enhanced acidity is likely derived from the superacidic metal oxide, which is strongly induced by the bonded SO and shows high electron deficiency . This is in agreement with the results of XPS showing improved binding energies for all the metal elements after sulfation.…”

“…It means that the sulfation improves the acidity of the catalysts to a large extent, and this acidity is mainly created by a large amount of Lewis acid sites and a very small amount of Brønsted acid sites. This is in accordance with the superacid theory given by Yamaguchi and Tanabe, who proposed that the metal center of SOM 0 (M 0 = metal center) was electronically induced by SO strongly, and strong Lewis acidity was created by the M 0 with high electron deficiency, while the Brønsted acid sites are possibly created by the presence of H 2 O . All the catalysts are prepared and tested isolated from moisture, hence only a small amount of Brønsted acid sites are observed.…”

Effect of nickel promoter on solvent‐free sulphated zirconia catalyst for the esterification of acetic acid with n‐butanol

“…The other similar peaks are near 2370 cm −1 , corresponding to organic residue from the precursors, and an intense peak near 1650 cm −1 due to the characteristic of non‐dissociated water molecules (δ HOH ) . From previous work, it is known that the IR bands of the sulphate groups are in the region of 900–1200 cm −1 . This work demonstrated that, in addition to two peaks at about 1250 cm −1 and 1160 cm −1 as observed for SZ, Ni‐SZ catalysts demonstrated two additional peaks of sulphate groups at about 1060 cm −1 and 1010 cm −1 .…”

“…As esterification is an acid‐catalyzed reaction, the rise of conversion with the increase of nickel is possibly due to the increase of sulphur content that bonded with nickel (supported by TGA‐DTG and XRF results), the increase of thermal stability of Ni‐SZ catalysts, and the formation of more sulphate groups compared to those of SZ (supported by FTIR results). Yamaguchi reported that the IR bands of the sulphate groups in the region of 900–1200 cm −1 exhibited high catalytic activity. Moreover, nickel incorporation also resulted in the formation of additional acid sites on the ZrO 2 support .…”

Synthesis of vinyl end‐capped polydimethylsiloxane by ring opening polymerization of octamethylcyclotetrasiloxane (D4) catalyzed by rare earth solid super acid SO42‐/TiO2/Ln3+

“…SO 4 2− /M x O y ‐type solid super acids have attracted a lot of attention owing to their high reactivity, ease of handling, good recovery, low waste generation, relative stability to moisture, air and heat, lower corrosiveness to reactors and containers, and above all environmental friendliness . Rare earth solid super acids SO 4 2− /TiO 2 /Ln 3+ , as a kind of sulfated metal oxide super acid, have been successfully developed from SO 4 2− /TiO 2 by modifying with the rare earth ion and have shown good behavior in initiating ring opening polymerization of chloromethyl thirane .…”