“… a HUSY-15F: HUYS treated with NH 4 F, T = 80 °C, WHSV = 3 h –1 , P = 2 MP, TOS = 2 h; V (isobutene)/ V (isobutane) = 40, ref . b HUSY-NS: HUYS treated with NH 4 (SO 4 ) 2 T = 80 °C, WHSV = 0.12 h –1 , P = 2 MP, TOS = 1.7 h; ref . c 50SZ/HZSM-5:50%SZ and 50%HZSM-5 combined catalyst, T = 80 °C, V (isobutene)/ V (isobutane) = 10; P = 1.4 MPa, feed flow rate = 2.0 mL/h; carrier gas flow rate = 1200 mL/h, ref . d CuHY-2%: T = 80 °C, WHSV of 1-butene = 0.1 h –1 , P = 2 MP, TOS = 2 h; V (isobutene)/ V (isobutane)=150, ref . …”