user12953: From theory I've encountered on the Catalan, I've understood that when black goes b7-b6 before first playing c7-c6, a good plan for white is to capture on d5. WI've understood that the rational for this might be that after black signaling that they might fianchetto, there's no longer a reason to keep not allow the exchange of the black e pawn, as their light squared bishop is anyway coming out, and that it's better for white that black recaptures with the e pawn than the c pawn (I'm guessing as after black later pushes the c pawn the hanging d- and c pawns might that become weak). However, I find it difficult to then come up with a follow up plan. What more breaks are there for white? Usually, when I still have my c pawn, I go for the e2-e4 break, but that seems less attractive in a case when there's no c pawn and I'd be landed with a isolated d pawn. Thoughts?

    
    [FEN "rnbq1rk1/p1p2ppp/1p2pn2/3p4/2PP4/5NP1/PP1NPPBP/R2QK2R w KQ - 0 8"]
1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Bb4+ 5. Bd2 Bxd2+ 6. Nbxd2 O-O 7. Bg2 b6 *



user14202: In double queen-pawn structure where x.cxd5 exd5 has occurred (sometimes called the Carlsbad structure) there is always the possibility of a "minority attack". This is more common in the QGD than in the Catalan but it is simply about the pawn islands.  As you alluded to Black could end up with "hanging pawns" if he plays for c7-c5.  If he doesn't, White will pile up on the c-file and push his 'a' and 'b' pawns hoping to isolate a black pawn and win it.
In your particular position you have traded dark-square bishops, so an eventual e2-e3 puts all your kingside pawns on dark-squares creating a very solid structure while you pressure d5 and the queen-side.

user14079: The idea of exchanging on d5 when Black goes for an early ...b6 is usually connected with play on the c-file: Nc3, Bf4, Rc1, maybe Qa4.
In this particular position, after ...Bxd2 Nbxd2, this plan is not available and the pawn exchange is much less promising. Here, you can stand with the main plan of preparing e2-e4 (with 0-0, Qc2, Rd1), or look for an opportunity to exploit the dark squares (Ne5, e3, and someday either f4, Ndf3 or c4-c5).
If memory serves, 6.Qxd2 is a bit more promising than 6.Nbxd2 in this line. 

12953: <p>From theory I've encountered on the Catalan, I've understood that when black goes b7-b6 before first playing c7-c6, a good plan for white is to capture on d5. WI've understood that the rational for this might be that after black signaling that they might fianchetto, there's no longer a reason to keep not allow the exchange of the black e pawn, as their light squared bishop is anyway coming out, and that it's better for white that black recaptures with the e pawn than the c pawn (I'm guessing as after black later pushes the c pawn the hanging d- and c pawns might that become weak). However, I find it difficult to then come up with a follow up plan. What more breaks are there for white? Usually, when I still have my c pawn, I go for the e2-e4 break, but that seems less attractive in a case when there's no c pawn and I'd be landed with a isolated d pawn. Thoughts?</p>

<pre>
<code>    
    [FEN "rnbq1rk1/p1p2ppp/1p2pn2/3p4/2PP4/5NP1/PP1NPPBP/R2QK2R w KQ - 0 8"]
1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Bb4+ 5. Bd2 Bxd2+ 6. Nbxd2 O-O 7. Bg2 b6 *
</code>
</pre>
 14202: <p>In double queen-pawn structure where x.cxd5 exd5 has occurred (sometimes called the Carlsbad structure) there is always the possibility of a "minority attack". This is more common in the QGD than in the Catalan but it is simply about the pawn islands.  As you alluded to Black could end up with "hanging pawns" if he plays for c7-c5.  If he doesn't, White will pile up on the c-file and push his 'a' and 'b' pawns hoping to isolate a black pawn and win it.</p>

<p>In your particular position you have traded dark-square bishops, so an eventual e2-e3 puts all your kingside pawns on dark-squares creating a very solid structure while you pressure d5 and the queen-side.</p>
 14079: <p>The idea of exchanging on d5 when Black goes for an early ...b6 is usually connected with play on the c-file: Nc3, Bf4, Rc1, maybe Qa4.</p>

<p>In this particular position, after ...Bxd2 Nbxd2, this plan is not available and the pawn exchange is much less promising. Here, you can stand with the main plan of preparing e2-e4 (with 0-0, Qc2, Rd1), or look for an opportunity to exploit the dark squares (Ne5, e3, and someday either f4, Ndf3 or c4-c5).</p>

<p>If memory serves, 6.Qxd2 is a bit more promising than 6.Nbxd2 in this line. </p>
