Your autoexec.cfg must be saved in "..\steamapps\common\Half-Life 2 Update\hl2\cfg"

Otherwise it won't work.

// ****************************************************************
// *
// Half-Life 2 AUTOEXEC.cfg by genu © 2007 *
// *
// ****************************************************************
sv_cheats "1" // enables cheats
con_enable "1" // enables the console

unbindall // unbind all keybinds
//******************
//* MOVEMENT *
//******************
// Movement
bind "w" "+forward" // Move forward
bind "s" "+back" // Move backwards
bind "a" "+moveleft" // Strafe left
bind "d" "+moveright" // Strafe right

// Stance
bind "SPACE" "+jump" // Jump
bind "c" "+duck" // Duck
//bind "CTRL" "+duck" // Duck
bind "SHIFT" "+speed" // Run
//bind "ALT" "+walk" // Walk

//*****************
//* WEAPONS *
//*****************
// Weapon control
bind "q" "lastinv" // Last used Weapon
bind "g" "phys_swap" // Switch to Graviton
bind "r" "+reload" // Reload
bind "z" "+zoom" // Binoculars

// Weapon slots
bind "1" "slot1" // Crowbar / Gravitron
bind "2" "slot2" // 9-mm Pistol / .357 Magnum
bind "3" "slot3" // SMG Sub-Machinengun / Impulsgun
bind "4" "slot4" // Shotgun / Crossbow
bind "5" "slot5" // Grenade / RPG
bind "6" "slot6" // Pheropod (Bait)

// Munition
//bind "7" "give item_ammo_pistol_large" // Pistol-Ammo
//bind "8" "give item_ammo_357" // Magnum-Ammo
//bind "9" "give item_ammo_smg1" // SMG-Ammo
//bind "0" "give item_ar2_grenade" // SMG-Ammo

//bind "i" "give item_ammo_ar2" // Impulsgun-Ammo
//bind "o" "give item_ammo_crossbow" // Crossbow-Ammo
//bind "p" "give item_ml_grenade" // RPG-Ammo
//
//bind "h" "give item_healthkit" // 25 Life Medikit
//bind "j" "give item_battery" // 15 Energy Cells
//
//bind "b" "give item_box_buckshot" // Shotgun-Ammo
bind "7" "give weapon_smg1" // Get SMG
bind "8" "give weapon_ar2" // Get Impulsgun
bind "9" "give weapon_shotgun" // Get Shotgun

//bind "l" "give item_box_srounds" // Pistol-Ammo
//bind "m" "give item_box_sniper_rounds" // Crossbow-Ammo
//bind "n" "give item_box_mrounds" // SMG-Ammo

//bind "n" "give weapon_pistol" // Get 9-mm Pistol
//bind "n" "give weapon_smg1" // Get SMG
//bind "n" "give weapon_frag" // Get Genade
//bind "n" "give weapon_rpg" // Get RPG

//*********************
//* Interaction *
//*********************
bind "e" "+use" // Use Object/Switch/Machines
bind "v" "impulse 50" // Command Units default: C
bind "f" "impulse 100" // Flashlight on/off default: F

//**************************
//* MENUS AND SCORES *
//**************************
bind "ESCAPE" "cancelselect" // Toggle Main Menu
bind "`" "toggleconsole" // Toggle Console
bind "INS" "toggleconsole" // Toggle Console
bind "`" "toggleconsole" // Toggle Console
bind "PAUSE" "pause" // Pause the game

//***********************
//* VERSCHIEDENES *
//***********************
// F-Keys
bind "F1" "god" // God Mode
bind "F2" "buddha" // God Mode. Spieler rceives damage but cannot die.
bind "F3" "notarget" // Enemies can't see you
bind "F4" "noclip" // Walk through walls

bind "F5" "save quick" // Quick save
bind "F6" "impulse 101" // Gives the player all weapons, full ammo, extra health and extra energy.
bind "F7" "ch_createjeep" // Creates a jeep
bind "F8" "ch_createairboat" // Creates a hoovercraft

bind "F9" "load quick" // Quick load
bind "F10" "quit" // Quit game
//bind "F11" "showtriggers_toggle" // Show target trigger on/off
bind "F12" "jpeg" // Screenshot

//*******************
//* NUM-BLOCK *
//*******************
//bind KP_STAR "give weapon_frag" // Grenade
bind KP_PLUS "give item_healthkit" // 25 Life first-aid kit
bind KP_MINUS "give item_battery" // 15 Battery cell

bind KP_HOME "give item_ml_grenade" // RPG-Ammo //7
bind KP_UPARROW "give item_ammo_crossbow" // Crossbow ammo //8
bind KP_PGUP "give weapon_frag" // Grenade //9

bind KP_LEFTARROW "give item_ar2_grenade" // SMG-Grenade //4
bind KP_5 "give item_box_buckshot" // Shotgun ammo pack //5
bind KP_RIGHTARROW "give item_ammo_ar2" // Impulse rifle ammo //6

bind KP_END "give item_ammo_pistol_large" // Pistol ammo //1
bind KP_DOWNARROW "give item_ammo_357" // Magnum ammo //2
bind KP_PGDN "give item_ammo_smg1" // SMG ammo //3

//***************
//* MOUSE *
//***************
bind "MOUSE1" "+attack" // Primary attack
bind "MOUSE2" "+attack2" // Secondary attack
//bind "MOUSE3" "+zoom" //
bind "MOUSE4" "+jump" // jump
bind "MOUSE5" "+duck" // Duck
bind "MWHEELDOWN" "invnext" // Next weapon
bind "MWHEELUP" "invprev" // Previous weapon

// ****************************************************************
// Tweaks
// ****************************************************************
// Sets the amount of ammo in each ammunition package
sk_max_buckshot 180
sk_plr_dmg_buckshot 25
sk_plr_num_shotgun_pellets 75
sk_max_smg1 900
sk_plr_dmg_smg1 200
sk_max_pistol 540
sk_plr_dmg_pistol 250

//***************
// DuckJump
//***************
alias +duckjump "+jump; wait; +duck"
alias -duckjump "-jump; wait; -duck"
bind "ALT" "+duckjump"

//**************
// FPS display *
//**************
alias fps_on_off "switch_fps_on_off"
alias switch_fps_on_off_s "cl_showfps 1; alias fps_on_off switch_fps_on_off"
alias switch_fps_on_off "cl_showfps 0; alias fps_on_off switch_fps_on_off_s"
bind "F11" "fps_on_off"