Proton conducting titanate, polymer nano-composite membrane including the same, and fuel cell adopting the polymer nano-composite membrane

A polymer nano-composite membrane comprising

• a proton conducting polymer;
• and
• a proton conducting titanate comprising:
• titanate of the formula H2Ti3O7;
• and
• a sulfonic acid group-containing moiety having proton conductivity introduced into the surface of the titanate,
• wherein the sulfonic acid group-containing moiety is directly bound to the titanate via an ether bond (—O—) and wherein the sulfonic acid group-containing moiety is
• —O-AR1SO3H
• wherein R1 is a substituted or unsubstituted C1-C12 alkylene group or a substituted or unsubstituted C1-C12 alkenylene group, A is —C(R′)(R″)— or —C═O—, and R′ and R″ are each independently hydrogen or a C1-C10 alkyl group, or R′ and R″ together form a ring represented by the following formula:
• wherein * represents the position where R′ and R″ are attached to carbon;
• or
• —O—C(R2)(X)C(Y1)(Y2)SO3H
• wherein R2 is —F, —Cl, —SF5, ═SF4, —SF4Cl, —CF3, —CF2CF3, —H(CF2)4, a C1-C12 alkyl group, a C1-C12 halogenated alkyl group, a C1-C12 alkenyl group, a C1-C12 halogenated alkenyl group, —CF2OSO2F, —(CF2)4CHFSO2F, —CF2CF2CHFSO2F, —CF2CHFSO2F, —CF2OCF(CF3)CF3, —CF2C(═CF2)F, —CF2OCF3, —CF2C(F)(Cl)CF2CCl2F, —CH2CH(Cl)CH2Cl, or a group represented by the following formula:
• wherein X is —F, —H, —Cl or —CF3, and Y1 and Y2 are each independently F or Cl.