The generator matrix

 1  0  1  1  1  0  1  1  1  0  1  0
 0  1  1  0  1  1  0  X X+1  1  1  1
 0  0  X  0  0  0  0  0  0  X  X  X
 0  0  0  X  0  0  0  X  0  X  0  X
 0  0  0  0  X  0  0  0  X  X  0  X
 0  0  0  0  0  X  0  0  X  X  X  0
 0  0  0  0  0  0  X  X  X  0  X  0

generates a code of length 12 over Z2[X]/(X^2) who´s minimum homogenous weight is 8.

Homogenous weight enumerator: w(x)=1x^0+55x^8+128x^10+144x^12+128x^14+55x^16+1x^24

The gray image is a linear code over GF(2) with n=24, k=9 and d=8.
As d=8 is an upper bound for linear (24,9,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 9.
This code was found by Heurico 1.16 in 3.81e-009 seconds.