In the last quarters a new class of solid superacids, including sulfated zirconium-hafnium oxides and ZrO[sub 2]/SO[sub 4] modified by Mn and Fe, were synthesized and shown to be active for isomerization and hydrocracking of hexadecane (n-C[sub 16]H[sub 34]). The reaction was carried out in a tubing bomb under mild conditions: 2.5 MPa and 433 K. Pt/HfO[sub 2]S0[sub 4] catalyst exhibited a low activity for hydrocracking of n-C[sub 16], but the addition of ZrO[sub 2] to the sulfated hafnium improved its activity considerably. An 85 wt % conversion level was achieved when the molar ratio of ZrO[sub 2] to HfO[sub 2] reached 1:1, indicating the possibility of a synergistic effect between zirconium and hafnium. It has recently been reported that Mn,Fe/ZrO[sub 2]/SO[sub 4] is about three orders of magnitude more active than ZrO[sub 2]/SO[sub 4] for isomerizing n-butane. As a result, an 0.5%Mn1.5%Fe/ZrO[sub 2]/SO[sub 4] catalyst was prepared according to a procedure given in a patent. It was found that, without Pt, the catalyst was inactive for hydrocracking of n-C[sub 16], possibly by deactivation due to coking. It is interesting that a 68 wt % conversion level was achieved after incorporation of Pt along with a product distribution that was …

In the last quarters a new class of solid superacids, including sulfated zirconium-hafnium oxides and ZrO{sub 2}/SO{sub 4} modified by Mn and Fe, were synthesized and shown to be active for isomerization and hydrocracking of hexadecane (n-C{sub 16}H{sub 34}). The reaction was carried out in a tubing bomb under mild conditions: 2.5 MPa and 433 K. Pt/HfO{sub 2}S0{sub 4} catalyst exhibited a low activity for hydrocracking of n-C{sub 16}, but the addition of ZrO{sub 2} to the sulfated hafnium improved its activity considerably. An 85 wt % conversion level was achieved when the molar ratio of ZrO{sub 2} to HfO{sub 2} reached 1:1, indicating the possibility of a synergistic effect between zirconium and hafnium. It has recently been reported that Mn,Fe/ZrO{sub 2}/SO{sub 4} is about three orders of magnitude more active than ZrO{sub 2}/SO{sub 4} for isomerizing n-butane. As a result, an 0.5%Mn1.5%Fe/ZrO{sub 2}/SO{sub 4} catalyst was prepared according to a procedure given in a patent. It was found that, without Pt, the catalyst was inactive for hydrocracking of n-C{sub 16}, possibly by deactivation due to coking. It is interesting that a 68 wt % conversion level was achieved after incorporation of Pt along with a product distribution that was …

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification: Construction of section 415.058 of the Government Code, addressing the effect of a felony conviction on the leisure of a law enforcement officer (RQ-207)

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification: Whether a school district’s purchases of gasoline for use by an independent contractor in the provision of transportation services for the school district are exempt from the gasoline tax (RQ-497)

Weekly newsletter discussing natural resources, parks, hunting and fishing, and other information related to the outdoors in Texas.

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.